Tomato-potato gratin is the kind of dish that fills the kitchen with the best smell and lands on the table looking like a real showstopper. It’s perfect for cozy family dinners, easy entertaining, or any night you want something warm and satisfying without a lot of fuss.
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The key is thinly sliced potatoes, ripe tomatoes, and a simple garlic-infused cream that ties everything together. Layer it right, bake it golden, and you get tender, saucy layers under a bubbly cheese crust.
Why This Recipe Works
This recipe is about building layers of flavor, not adding complexity. Gently simmering the cream with garlic and nutmeg gives it a subtle, aromatic backbone without sharp raw garlic bite. Thin potato slices absorb the cream as they bake, turning silky and tender all the way through. Fresh tomato rounds add pockets of bright acidity that cut through the richness, so no bite feels heavy. A two-cheese finish with mozzarella and Parmesan gives you both melt and crunch.
In short, simple layering with well-seasoned cream makes this gratin taste far more refined than the effort suggests.
What You’ll Need
500 g (1.1 lbs) potatoes, peeled and thinly sliced (about 3 mm thick)
2 medium tomatoes, sliced into rounds
150 g (1.5 cups) shredded mozzarella
30 g (1/3 cup) grated Parmesan
200 ml (3/4 cup) heavy cream or crème fraîche (35% fat)
50 ml (1/4 cup) milk
1 garlic clove, lightly crushed (skin on)
A pinch of nutmeg
A pinch of black pepper
Salt, to taste
Butter, for greasing the dish
A few fresh basil leaves, for garnish
Equipment: baking dish, small saucepan, mandoline or sharp knife, aluminum foil or parchment paper
Step-by-Step Instructions
Infuse the cream. Combine heavy cream, milk, nutmeg, black pepper, salt, and the lightly crushed garlic clove (skin on) in a small saucepan. Heat over low, stirring gently, until the mixture reaches a soft simmer, about 5 minutes. Remove from heat, discard the garlic, and let it cool slightly. This step builds a warm, aromatic base without any harsh garlic punch.
Prep the oven and dish. Preheat your oven to 180°C (350°F). Grease a baking dish with butter, making sure to coat the bottom and sides so nothing sticks.
Slice the potatoes. Peel and slice potatoes thinly and evenly, about 3 mm thick. A mandoline makes this fast and consistent, but a sharp knife and steady hand work fine. Even slices mean even cooking.
Slice the tomatoes. Cut tomatoes into rounds of similar thickness. Shake off any excess juice so the layers don’t get waterlogged.
Build the first layer. Arrange a single layer of potato slices across the bottom of the dish, overlapping slightly. Drizzle a few spoonfuls of the cream mixture over the top. Scatter a handful of mozzarella and a light dusting of Parmesan.
Add the tomato layer. Place tomato slices in a single layer over the cheese. This creates pockets of bright flavor between the starchy, creamy potato layers.
Repeat the layers. Continue alternating potato and tomato layers, drizzling cream and sprinkling cheese as you go. Finish with a final layer of potatoes topped generously with the remaining mozzarella and Parmesan. Pour any leftover cream mixture evenly over the top.
Cover and bake. Cover the dish tightly with foil or parchment paper. Bake for 40 minutes. The cover traps steam, which helps the potatoes cook through and absorb the cream.
Uncover and brown. Remove the foil and bake for another 10 minutes until the cheese is golden, bubbly, and lightly crisp around the edges.
Rest and garnish. Let the gratin rest for 5 minutes before serving. This lets the layers firm up slightly so slices hold together. Scatter fresh basil leaves over the top for a pop of color and fragrance.
Tomato Potato Gratin
Tender potatoes, juicy tomatoes, and garlic-infused cream under a golden cheese crust — cozy, simple, and deeply satisfying
Ingredients
- 500 g (1.1 lb) potatoes, peeled and thinly sliced (about 3 mm thick)
- 2 medium tomatoes, sliced into rounds
- 150 g (1½ cups) shredded mozzarella
- 30 g (1/3 cup) grated Parmesan
- 200 ml (3/4 cup) heavy cream or crème fraîche
- 50 ml (1/4 cup) milk
- 1 clove garlic, lightly crushed with the skin on
- Pinch of nutmeg
- Pinch of black pepper
- Salt, to taste
- Butter, for greasing the dish
- Few fresh basil leaves, for garnish
Optional Variations
- Gruyère, fontina, or sharp cheddar instead of some or all of the mozzarella
- Fresh thyme, rosemary, or Italian herbs instead of basil
- Thinly sliced zucchini or roasted red peppers
- Caramelized onions
- Prosciutto, cooked bacon, or shredded rotisserie chicken for a heartier version
- Plant-based cheese and cream for a dairy-free version
Instructions
- Infuse the CreamIn a small saucepan, combine the heavy cream or crème fraîche, milk, nutmeg, black pepper, salt, and the lightly crushed garlic clove. Heat over low, stirring gently, until the mixture reaches a soft simmer, about 5 minutes. Remove from the heat, discard the garlic, and let the cream cool slightly.This gives the gratin a mellow garlic flavor without any harsh raw bite.
- Prep the Oven and DishPreheat the oven to <strong>180°C (350°F)</strong>. Butter a baking dish well, coating both the bottom and the sides so the gratin releases easily after baking.A shallow dish gives you better browning and helps the center cook more evenly.
- Slice the Potatoes and TomatoesPeel and slice the potatoes thinly and evenly, about <strong>3 mm</strong> thick. Slice the tomatoes into rounds of similar thickness and gently shake off any excess juice.Even slicing is important — thick or uneven potatoes may stay firm in the center.
- Build the First LayerArrange a single layer of potato slices across the bottom of the baking dish, overlapping slightly. Drizzle over a few spoonfuls of the cream mixture, then scatter on a handful of mozzarella and a light sprinkle of Parmesan.Do not flood the layers with cream — the potatoes will absorb more as they bake.
- Add the Tomato LayerArrange a layer of tomato slices over the cheese. This adds pockets of bright acidity that balance the creamy potatoes and rich cheese.
- Repeat the LayersContinue alternating potato and tomato layers, drizzling with cream and sprinkling cheese as you go. Finish with a final layer of potatoes, then top generously with the remaining mozzarella and Parmesan. Pour any remaining cream evenly over the top.Finish with potatoes on top so the cheese browns evenly and forms a proper gratin crust.
- Cover and BakeCover the dish tightly with foil or parchment paper and bake for <strong>40 minutes</strong>. The cover traps steam so the potatoes soften fully and absorb the cream.Do not skip the covered bake or the top may brown before the potatoes turn tender.
- Uncover and BrownRemove the cover and bake for another <strong>10 minutes</strong>, until the cheese is golden, bubbly, and lightly crisp around the edges.If you want deeper color, broil very briefly at the end, watching closely.
- Rest and ServeLet the gratin rest for about <strong>5 minutes</strong> before serving so the layers can firm up slightly. Garnish with fresh basil leaves and serve warm.Resting helps the slices hold together more neatly.
Tips for the Best Results
- Slice the potatoes thinly and evenly so they cook through at the same rate.
- Shake off excess tomato juice before layering so the gratin does not turn watery.
- Season the cream well because it carries the flavor through the whole dish.
- Do not overdo the cream — the potatoes absorb liquid as they bake, and too much can make the gratin runny.
- Always cover the gratin for the first part of baking so the potatoes steam and soften properly.
- Let the dish rest for 5 minutes before serving for cleaner slices and better texture.
- A mandoline is the easiest way to get uniform potato slices, but a sharp knife works well too.
- You can assemble the gratin up to 12 hours ahead, refrigerate it covered, and add about 10 extra minutes to the covered bake time.
- Leftovers keep in the fridge for up to 3 days and reheat best in the oven at <strong>160°C (325°F)</strong> for 15–20 minutes.
- This gratin does not freeze especially well because the tomatoes release water and soften too much after thawing.
How to Store
Tomato-potato gratin keeps well in the refrigerator for up to 3 days. Let it cool to room temperature, then cover the dish tightly or transfer portions to an airtight container. Reheat in the oven at 160°C (325°F) for 15 to 20 minutes until warmed through. Microwaving works in a pinch but can make the top lose its crispness.
This gratin does not freeze well. The tomatoes release water on thawing, which makes the layers soggy and the texture uneven.
Health Benefits
Potassium from potatoes: Potatoes are a solid source of potassium and vitamin C, supporting heart function and immune health.
Lycopene from tomatoes: Cooked tomatoes are rich in lycopene, a powerful antioxidant linked to heart and skin health.
Calcium boost: Mozzarella and Parmesan contribute calcium, which supports bone strength and muscle function.
Balanced comfort: Pairing starchy potatoes with fresh tomatoes and herbs gives this dish a more rounded nutritional profile than many heavy gratins.
Pitfalls to Watch Out For
Thick potato slices: Unevenly or thickly cut potatoes won’t cook through in time and stay crunchy in the center. Aim for 3 mm or thinner.
Too much tomato juice: Watery tomatoes can make the gratin soggy. Shake off excess juice before layering, or use firmer varieties like Roma.
Skipping the covered bake: Without foil for the first stretch, the top browns before the potatoes are tender. Always cover first, then uncover to finish.
Overloading the cream: Resist the urge to flood the layers. The potatoes absorb cream as they bake, and too much liquid makes for a runny gratin.
Cutting too soon: Slicing right out of the oven means the layers haven’t set. Let it rest 5 minutes for cleaner slices.
Bland seasoning: The cream carries the flavor, so season it well. Under-salted cream means a flat-tasting gratin no matter how good the cheese is.
Jump to RecipeAlternatives
Cheese swaps: Try gruyère for a nuttier flavor, fontina for extra melt, or a sharp cheddar for a bolder finish. A mix of cheeses often gives the best results.
Cream options: Swap heavy cream for crème fraîche for a tangier sauce, or use a light cream for a slightly less rich version. Coconut cream works for a dairy-free take.
Herb variations: Replace basil with fresh thyme, rosemary, or a mix of Italian herbs. Dried herbs work in a pinch—just use about half the amount.
Extra vegetables: Thinly sliced zucchini, roasted red peppers, or caramelized onions layer beautifully between the potatoes and tomatoes.
Protein additions: Lay thin slices of prosciutto or cooked bacon between layers for a heartier meal.
Vegan version: Use dairy-free cheese, plant-based cream, and a drizzle of olive oil in place of butter. Season the cream generously to keep the flavor rich.
FAQ
Can I Use a Mandoline for the Potatoes?
Absolutely, and it’s the easiest way to get thin, uniform slices. Set it to about 3 mm. If you don’t have one, a sharp knife works—just take your time and keep the slices as even as possible. Consistent thickness matters more than perfect thinness.
Do I Need to Par-Boil the Potatoes First?
No. The thin slices cook through in the oven, especially with the covered bake step. Par-boiling adds time and can make the slices fragile, causing them to break when you layer.
Can I Assemble This Ahead of Time?
Yes. Build the gratin, cover, and refrigerate for up to 12 hours before baking. Add about 10 extra minutes to the covered bake time since it’s starting cold. The flavors actually meld a bit more this way.
Why Are My Layers Watery?
Usually the tomatoes are to blame. Use firm, ripe tomatoes and shake off seeds and excess juice before layering. Overloading the cream can also cause this. The gratin should be saucy, not swimming.
Can I Make This Without Mozzarella?
Yes. Mozzarella gives the classic stretchy melt, but gruyère, fontina, or even a good melting cheddar work well. The Parmesan on top is what gives the golden crust, so keep that in either way.
Jump to RecipeWhat’s the Best Baking Dish to Use?
A shallow, wide dish works best. It gives you more surface area for a golden top and ensures the heat reaches the center. Ceramic and glass are both good choices. Avoid very deep dishes—the middle layers may stay undercooked.
Can I Add Meat to This?
Thin slices of prosciutto, cooked bacon, or even shredded rotisserie chicken layer in nicely between the potatoes and tomatoes. Just keep the layers thin so everything bakes evenly.
Wrapping Up
Tomato-potato gratin is warm, cheesy, and comforting without being complicated. With thinly sliced potatoes, ripe tomatoes, and a garlic-kissed cream holding it all together, every layer pulls its weight. Top it with bubbly mozzarella and Parmesan, finish with fresh basil, and you have a dish that looks and tastes like you spent far more time than you actually did.
Serve it alongside a simple salad or crusty bread, and let the gratin be the star.
