Tomato Potato and Leek Gratin Recipe
This Tomato Potato and Leek Gratin recipe is the cozy side dish that quietly steals the dinner table spotlight. Thinly sliced Yukon gold potatoes, tender buttery leeks, juicy tomatoes, fresh herbs, cream, and Parmigiano-Reggiano bake together into a bubbling, golden gratin that feels fancy enough for a holiday meal but simple enough for Sunday dinner.
Dinner can be a challenge when everyone has different favorites, but potatoes usually bring the peace treaty. You can slice them, dice them, mash them, bake them, fry them, and tuck them into a creamy gratin like this one. If my family were stranded on a desert island and could only choose one food, potatoes would absolutely be in the running.
This Tomato Potato and Leek Gratin brings together three of my favorite flavors and textures: tender potatoes, sweet leeks, and bright tomatoes. It is colorful, comforting, easy to serve, and delicious alongside roasted chicken, pork chops, steak, ham, turkey, seafood, or a simple green salad.
Why You’ll Love This Tomato Potato and Leek Gratin
- It is a beautiful side dish. The tomatoes add color and brightness, making this gratin stand out on the table.
- It feels special without being difficult. The layers look impressive, but the steps are simple and approachable.
- It works for holidays and weeknights. Serve it for Thanksgiving, Christmas, Easter, Sunday supper, or a cozy family dinner.
- It pairs with almost everything. Potatoes, tomatoes, and leeks are easy to serve with chicken, beef, pork, seafood, or vegetarian mains.
- It is comfort food with a garden-fresh twist. Creamy potatoes meet bright tomatoes and sweet, buttery leeks.
What Is Tomato Potato and Leek Gratin?
A gratin is a baked dish that usually features layers of vegetables, cream, cheese, and a golden browned top. This version layers thinly sliced potatoes with softened leeks and seasoned tomatoes, then finishes with Parmigiano-Reggiano for a savory, bubbling casserole-style side dish.
You can call it Tomato Potato and Leek Gratin or Potato Tomato and Leek Gratin. Either way, you are getting a creamy, cheesy, herby potato side dish with just enough tomato brightness to keep every bite interesting.
The Secret to Big Flavor
The tomatoes are what make this gratin extra beautiful and flavorful. I love the color and richness they bring to the dish. The tomatoes add brightness against the cream, cheese, and tender potatoes, creating a side dish that feels cozy but not heavy.
I have used Tuttorosso tomatoes in other favorites like my hearty minestrone recipe and authentic easy Italian sauce recipe. They help create that deep tomato flavor and rich color that makes a finished dish look as good as it tastes. You can also read more in my Tuttorosso Tomatoes vs. Hunt’s Tomatoes challenge.
Tomato Potato and Leek Gratin Ingredients
This recipe uses simple ingredients, but each one adds something important. The potatoes bring the creamy comfort, the leeks add sweetness, the tomatoes add brightness, and the cheese gives the top that golden gratin finish.
- 2 leeks
- 2 tablespoons butter
- 1 1/4 teaspoons salt, divided
- 5 medium potatoes, preferably Yukon gold
- 1 1/2 tablespoons extra virgin olive oil
- 1/2 teaspoon freshly ground black pepper
- 1 teaspoon fresh thyme, chopped
- 1 can Tuttorosso No Salt Added peeled Plum Italian Style Tomatoes, 28 ounces
- 1/2 cup fresh basil leaves, packed and torn into pieces
- 1 1/4 cups Parmigiano-Reggiano cheese, divided
- 1/2 cup heavy cream
How to Clean Leeks for Gratin
Leeks are delicious, but they can hide dirt between their layers. Do not skip the cleaning step. Most of the grit is found where the white part begins to turn green, so slicing and rinsing them carefully makes a big difference.
- Leave the roots intact and slice the leeks in half lengthwise.
- Rinse the layers under cold water to remove dirt.
- Cut off the dark green tops and discard them.
- Slice the leeks into 1/4-inch half-rounds down to the root.
- Discard the roots.
How to Make Tomato Potato and Leek Gratin
Step 1: Preheat the Oven
Preheat the oven to 400 degrees F.
Step 2: Prepare the Leeks
Leaving the roots intact, slice the leeks in half lengthwise. Rinse them under cold water to dislodge any dirt between the layers. Cut off the dark green parts and discard them. Slice the leeks into 1/4-inch half-rounds all the way down to the root, then discard the roots.
Step 3: Cook the Leeks
Melt the butter in a sauté pan over medium-low heat. Add the leeks and cook until wilted and tender, about 15 to 20 minutes. Remove from heat and season with 1/4 teaspoon salt.
Step 4: Slice and Season the Potatoes
Using a mandolin, slice the skin-on potatoes into 1/8-inch thick rounds. Place the slices in a bowl of cold water, rinse for about 10 seconds, and drain.
Place the drained potatoes in a bowl and toss with olive oil, 1/2 teaspoon salt, black pepper, and fresh thyme. Toss well and set aside.
Step 5: Prepare the Tomatoes
Drain the tomatoes in a colander. Working over the colander, gently open the tomatoes with your hands and tear them into large, flat chunks. Place the drained tomato pieces into a bowl.
Toss the tomatoes with 1/2 teaspoon salt, fresh basil, 3/4 cup Parmigiano-Reggiano cheese, and heavy cream.
Step 6: Layer the Gratin
In an 8×8-inch casserole dish, 9-inch cast-iron pan, or pie plate, spread 1/3 of the leeks in the bottom of the dish.
Layer 1/3 of the potato slices over the leeks, shingling them around in a circle until the surface is covered. Spread 1/3 of the tomato mixture over the potatoes.
Repeat the layers two more times.
Step 7: Bake Until Golden and Bubbling
Transfer the casserole to the oven and bake for 35 minutes.
Carefully remove the dish from the oven and sprinkle the remaining 1/2 cup Parmigiano-Reggiano cheese over the top. Return the casserole to the oven and bake for an additional 25 minutes, or until the surface is bubbling and the cheese has browned.
Step 8: Rest and Serve
Remove the gratin from the oven and let it cool for 5 minutes before serving. This short rest helps the layers settle so the gratin is easier to scoop and serve.
Expert Tips for the Best Potato Gratin
- Use Yukon gold potatoes if possible. They have a creamy texture and hold their shape well in layered baked dishes.
- Slice the potatoes evenly. A mandolin helps create thin, even slices so the potatoes cook at the same rate.
- Do not skip rinsing the potatoes. A quick rinse removes excess starch and helps the layers bake more cleanly.
- Cook the leeks low and slow. You want them tender and sweet, not browned and bitter.
- Drain the tomatoes well. Too much extra liquid can make the gratin watery.
- Let it rest before serving. Five minutes gives the cream, cheese, tomatoes, and potatoes time to settle.
Recipe Variations
This potato tomato and leek gratin is delicious as written, but it also gives you room to play with the flavors depending on your menu.
- Add garlic: Sauté a clove or two of minced garlic with the leeks for extra savory flavor.
- Make it cheesier: Add a little mozzarella, Gruyère, or fontina with the Parmigiano-Reggiano.
- Add breadcrumbs: Sprinkle seasoned breadcrumbs over the top with the final layer of cheese for extra crunch.
- Use rosemary: Swap the thyme for rosemary if you want a stronger holiday-style herb flavor.
- Add heat: A pinch of crushed red pepper flakes gives the tomatoes a little kick.
What to Serve with Tomato Potato and Leek Gratin
This gratin works anywhere you would serve a potato side dish, but the tomatoes and leeks make it especially good with roasted meats, holiday mains, and simple comfort food dinners.
- Roast chicken
- Pork chops
- Holiday ham
- Roasted turkey
- steak
- Seafood
- Meatloaf
- Grilled sausages
- A simple green salad
If you are building a full meal, this gratin also pairs well with other easy side dishes like Autumn Chopped Salad, Corn on the Cob, or Cuban Black Beans.
Make-Ahead and Storage Tips
Can I Make Tomato Potato and Leek Gratin Ahead of Time?
Yes. You can prepare the components ahead of time, then assemble and bake before serving. For best texture, slice and rinse the potatoes close to assembly time so they do not discolor.
How to Store Leftovers
Store leftover gratin in an airtight container in the refrigerator for up to 3 days.
How to Reheat
Reheat individual portions in the microwave or warm the gratin in a covered baking dish in the oven until heated through. If reheating in the oven, remove the cover for the last few minutes to help the top regain a little texture.
Can You Freeze Potato Gratin?
Potato gratins can be frozen, but the texture may change because potatoes and cream can become slightly grainy after thawing. For best results, enjoy this recipe fresh or refrigerated as leftovers.
Tomato Potato and Leek Gratin FAQs
What kind of potatoes are best for gratin?
Yukon gold potatoes are a great choice for gratin because they are naturally creamy, flavorful, and hold their shape well after baking. Russet potatoes can also work, but they may create a softer, starchier texture.
Do I have to peel the potatoes?
No. This recipe uses skin-on potatoes. The skins add texture, color, and a little rustic charm. If you prefer a smoother gratin, you can peel them first.
Can I use canned diced tomatoes?
Peeled plum tomatoes work well because they can be torn into larger pieces and layered throughout the gratin. Diced tomatoes may release more liquid and create a different texture, so drain them very well if using them as a substitute.
Can I make this gratin without a mandolin?
Yes, but slice the potatoes as thinly and evenly as possible with a sharp knife. Thin, even slices help the potatoes bake through properly.
Is this potato gratin good for Thanksgiving?
Yes. Tomato Potato and Leek Gratin is a beautiful Thanksgiving side dish because it adds color, creaminess, and comfort to the holiday table. It is also a nice change from traditional mashed potatoes.
Can I serve this as a vegetarian side dish?
Yes, this recipe works well as a vegetarian side dish if your cheese is vegetarian-friendly. Serve it with salads, roasted vegetables, grains, or a holiday vegetarian main.
Why is my gratin watery?
A watery gratin usually comes from tomatoes that were not drained well enough or potatoes that released extra moisture. Drain the tomatoes thoroughly, rinse and drain the potatoes, and let the gratin rest for 5 minutes before serving.
More Easy Side Dish Recipes to Round Out Your Meal
Looking for something delicious to serve with dinner, bring to a potluck, or add to your holiday table? These easy side dish recipes make it simple to build a complete meal, whether you need potatoes, beans, salads, dips, vegetables, or BBQ sides.
- Pumpkin Mashed Potatoes — A cozy fall side dish for Thanksgiving, holiday dinners, pork, turkey, and comfort food meals.
- Tomato Potato Leek Gratin — A warm baked potato side dish that works beautifully for Sunday dinner, holidays, and cozy family meals.
- How to Shuck and Cook Corn on the Cob — A classic summer side dish for BBQs, cookouts, Memorial Day, Fourth of July, and backyard dinners.
- Cuban Black Beans — A flavorful bean side dish for rice bowls, tacos, grilled meats, pork, chicken, and Latin-inspired meals.
- Instant Pot Black Beans — A budget-friendly meal prep side for taco night, burrito bowls, rice, and easy weeknight dinners.
- Copycat Taco Bell Pintos and Cheese — A cheesy bean side dish perfect for taco night, Tex-Mex dinners, game day, and copycat restaurant meals.
- How to Cook Perfect Rice in the Instant Pot — A simple staple side dish for beans, chicken, beef, seafood, stir-fry, and saucy dinners.
- Spiral Pasta with Pesto, Sun-Dried Tomatoes, and Pine Nuts — A flavorful pasta side for potlucks, cookouts, lunch spreads, and Mediterranean-inspired meals.
- Autumn Chopped Salad — A fresh seasonal salad for Thanksgiving, fall potlucks, harvest dinners, and cozy entertaining.
- Pineapple Mango Salsa — A bright fruit salsa for grilled chicken, fish tacos, pork, shrimp, BBQ dinners, and summer meals.
- Chunky Guacamole — A fresh avocado side, dip, or topping for taco night, nacho bars, burrito bowls, and game day spreads.
- Supreme Queso Dip — A cheesy party side for game day, nacho bars, taco night, potlucks, and casual entertaining.
Need even more ideas? Browse the full Easy Side Dish Recipes hub for potatoes, vegetables, rice, pasta, beans, salads, dips, holiday sides, BBQ sides, and potluck favorites.
More Recipes to Serve with This Gratin
If you love cozy side dishes and tomato-based comfort food, try this gratin alongside other Mommy’s Memorandum reader favorites. The tomatoes in this recipe also make it a natural match for hearty minestrone and authentic easy Italian sauce. For even more dinner inspiration, browse the full Easy Side Dish Recipes collection.
Final Thoughts
This Tomato Potato and Leek Gratin is the kind of side dish that makes a meal feel intentional. It has the comfort of potatoes, the sweetness of leeks, the brightness of tomatoes, and the golden cheesy finish every gratin deserves.
Serve it for holidays, Sunday dinner, potlucks, or any night when plain potatoes just are not going to cut it. It is warm, colorful, cozy, and ready to earn a permanent spot in your side dish rotation.
Save this Tomato Potato and Leek Gratin recipe for your next holiday meal, family dinner, or cozy comfort food menu.
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Ingredients
- 2 leeks
- 2 tablespoons butter
- 1-1/4 tsp salt
- 5 medium potatoes (I like Yukon gold)
- 1-1/2 tablespoons extra virgin olive oil
- 1/2 teaspoon freshly ground black pepper
- 1 teaspoon fresh thyme, chopped
- 1 (28 ounces) can Tuttorosso No Salt Added peeled Plum Italian Style Tomatoes
- 1/2 cup fresh basil leaves, packed and torn into pieces
- 1-1/4 cups Parmigiano-Reggiano cheese
- 1/2 heavy cream
Instructions
- Preheat oven to 400-degrees
- Leaving roots intact, slice leeks in half lengthwise. Rinse under cold water to dislodge any dirt between the layers. Most dirt is where the leek changes from white to green, about halfway up. Cut off dark green parts and discard. Slice the leeks into 1/4-inch half-rounds all the way down to the root. Discard roots.
- Melt butter in a saute pan over medium-low heat. Add the leeks and cook until wilted and tender, about 15-20 minutes. Remove from heat and season with 1/4 teaspoon salt.
- Using a mandolin, slice skin-on potatoes into 1/8-inch thick rounds. Place slices in a bowl of cold water, rinse for 10-seconds and drain. Place the drained potatoes in a bowl and toss with the olive oil, 1/2 tsp. salt, black pepper and fresh thyme. Toss well and set aside.
- Drain tomatoes in a colander. Working over the colander, use your hands to gently open the tomatoes and tear into large, flat chunks. Place drained tomato pieces into a bowl. Toss with 1/2 tsp salt, fresh basil, 3/4 cup Parmigiano-Reggiano and heavy cream.
- In an 8x8 inch casserole dish or a 9-inch cast-iron pan or a pie plate, spread 1/3 of the leeks in the bottom of the dish. Layer with 1/3 of the potato slices, shingling them around in a circle until the surface is covered. Spread 1/3 of the tomato mixture over the potatoes. Repeat two more times.
- Transfer casserole to the oven and bake 35 minutes. Briefly, remove from oven and sprinkle with remaining cheese. return casserole to oven and cook for an additional 25 minutes, until the surface is bubbling and the cheese has browned.
- Remove from oven and cool for 5 minutes and serve.