I make a small gratin like this whenever I want something comforting without committing to a giant casserole. It’s an ideal two-person dish: simple to prep, forgiving in the oven, and reliably cheesy. The recipe is scaled to a 7×5-inch baking dish, so you get a golden, bubbling top and tender potato slices every time.
This version uses one russet potato, a touch of onion, a little flour to thicken, butter for richness, and a mix of milk and cream so the layers stay creamy without turning soupy. The instructions keep everything straightforward and baked until fork-tender — no fancy plating required.
Serve it as a cozy main with a salad, or as a side alongside roasted chicken or a simple seared steak. It’s easy to adapt and easy to love, and I’ll walk through swaps, troubleshooting, storage, and seasonal serving ideas below so you get the best results from a very small pan.
Ingredients
- 7×5-inch baking dish — the size is important for layer depth and cooking time.
- 1 large russet potato (about 12 oz) thinly sliced and divided — russets give a fluffy texture; slices should be even for uniform cooking.
- 1/4 onion halved root to tip and thinly sliced — thin slices melt into the layers and add sweet onion flavor.
- 1/4 teaspoon salt divided — split between layers so seasoning is even.
- 1/8 teaspoon pepper divided — divide the pepper to season between layers.
- 1 heaping teaspoon all-purpose flour — helps thicken juices so the gratin isn’t runny.
- 1 tablespoon cold butter diced and divided — cold butter dotted on top creates pockets of richness as it melts.
- 1/2 cup (2 oz) shredded Cheddar cheese divided — split for a cheesy middle and a golden top.
- 1/3 cup milk — thins the cream slightly so the sauce is silky.
- 1/3 cup heavy cream — provides richness and helps form a creamy sauce.
Your Shopping Guide
Buy a russet that’s close to 12 ounces (about the size of a large apple). Too-large potatoes will create thicker layers that take longer to cook; too small and the gratin will be thin. If you don’t have a kitchen scale, a medium russet works fine.
For the cheese, a simple shredded Cheddar is called for. Pick a block and shred it yourself when possible — pre-shredded cheese often contains anti-caking agents that can affect melting. You’ll only need 2 ounces total, so most grocery packs are more than enough.
The dairy is minimal: a third cup each of milk and heavy cream. If you shop at a small store, grab small containers or measure from what you have at home. The butter should be cold and diced — the cold pieces create tiny molten spots as the gratin bakes.
Cheesy Potato Gratin for Two — Do This Next
- Preheat the oven to 400°F. Lightly grease the 7×5-inch baking dish.
- Thinly slice the 1 large russet potato (about 12 oz) into even slices. Divide the slices into two roughly equal piles.
- Take the 1/4 onion, halve it root-to-tip, then thinly slice the halves.
- Arrange half of the potato slices in an even layer in the prepared dish. Top the potatoes with all of the sliced onion, spreading it evenly.
- Sprinkle half of the 1/4 teaspoon salt and half of the 1/8 teaspoon pepper evenly over the onions. Sprinkle the heaping teaspoon of all-purpose flour evenly over the onions. Scatter half of the diced cold butter and sprinkle half of the shredded Cheddar over this layer.
- Add the remaining potato slices in an even layer over the first layer. Sprinkle the remaining salt and pepper, dot with the remaining diced butter, and sprinkle the remaining shredded Cheddar on top.
- Pour the 1/3 cup milk and 1/3 cup heavy cream evenly over the potatoes and cheese.
- Place a sheet of foil or a baking sheet on the oven’s bottom rack to catch any bubbling over. Put the gratin on the center rack and bake for 40 to 60 minutes, until the potatoes are fork-tender and the top is bubbly.
- Remove from the oven and let the gratin rest for five minutes before serving.
Why This Recipe is a Keeper
It’s scaled for two without sacrificing texture or flavor. Many gratins are written for a 9×13 pan; shrinking a recipe down can lead to dry or unevenly cooked layers. Here, the 7×5 dish gives the right ratio of liquid to potato so you get creamy interior layers and a golden top.
The method balances simplicity with technique: splitting the potato slices into two piles and seasoning between layers ensures every bite is seasoned and cheesy. The flour is a small but crucial addition — it thickens the dairy juices so the gratin sets rather than running.
Swap Guide
- Cheese: Swap Cheddar for Gruyère or Fontina for a nuttier, meltier flavor. Use the same weight (2 oz total) even if flavors change.
- Potato: Yukon Golds can be used if you prefer a waxier texture; they’ll hold shape more but may yield a slightly different mouthfeel.
- Onion: If you don’t have an onion, a few thin slices of shallot work well and are milder. Keep the amount similar.
- Dairy: For a lighter version, use all milk, but the gratin will be less rich and might need a slightly longer bake to set. Keep the combined liquid roughly the same volume.
- Butter: If you need to reduce fat, use smaller dots of butter, but don’t omit entirely — the butter contributes flavor and browning.
Equipment & Tools
- 7×5-inch baking dish — the recipe is calibrated for this size.
- Sharp knife or mandoline — for even potato slices; a mandoline speeds this up but use caution.
- Cutting board — halving and slicing the onion and potato.
- Measuring cups and spoons — for the milk, cream, flour, salt, and pepper.
- Small bowl or plate — to hold divided potato slices while you layer.
- Aluminum foil or baking sheet — placed on the oven’s bottom rack to catch drips.
Problems & Prevention
Bubbly but raw
Problem: The top is brown and bubbly but the potatoes are still firm inside.
Prevention: Slice potatoes as thinly and evenly as possible. If slices vary widely, thicker pieces will take longer. Tent the dish with foil for part of the bake if the top is browning too fast; remove foil for the last 10–15 minutes to finish browning.
Runny gratin
Problem: After resting, the gratin is still soupy.
Prevention: Make sure you split the flour across the middle layer as directed; that teaspoon is doing important thickening work. Also rest the gratin for the full five minutes to allow the sauce to set. If it still seems loose, a few extra minutes in the oven help evaporate excess liquid.
Top burns before potatoes cook
Problem: The cheese is very dark while the interior needs more time.
Prevention: Move the dish to a lower rack and loosely tent with foil for the remainder of the bake. The foil prevents the top from scorching while the inside cooks through.
Spring–Summer–Fall–Winter Ideas
Spring: Pair the gratin with a bright lemony arugula salad and spring peas to cut the dish’s richness. A scattering of fresh herbs like chives or tarragon adds freshness.
Summer: Serve alongside grilled vegetables and a tomato salad dressed with vinaigrette. A light protein like grilled fish balances the dish on a warm night.
Fall: Add roasted root vegetables and a roasted chicken breast. Sprinkle a pinch of smoked paprika into the top layer for a warm, autumnal note.
Winter: Make it the centerpiece of a cozy meal with braised greens and roasted pork. Finish with a little cracked black pepper and a side of pickled vegetables to lift the richness.
Cook’s Notes
Mandoline users: If you own a mandoline, set it for medium-thin slices and always use the guard. Consistent thickness speeds up and evens out baking.
Resting matters: The five minutes of rest stated in the recipe isn’t arbitrary. The gratin firms up as it cools slightly, making it easier to serve clean slices and preventing a puddle on the plate.
Layering: Don’t crowd the slices. Overlapping is fine, but aim for a mostly even, single-stack layer each time to ensure heat reaches every slice.
Best Ways to Store
Refrigerate: Cool the gratin to room temperature, cover tightly with plastic wrap or transfer to an airtight container, and refrigerate for up to 3 days. Reheat in a 350°F oven until warmed through (about 15–20 minutes), which helps maintain texture better than microwave reheating.
Freeze: I don’t recommend freezing this small gratin—the cream and texture change after thawing. If you must, freeze before baking in a freezer-safe container, thaw overnight in the fridge, then bake until hot and bubbly; expect some texture change.
Ask the Chef
Q: Can I double the recipe?
A: Yes. Use a larger dish (9×13 or similar) and expect longer baking time. Keep an eye on doneness and use a foil tent if the top browns too quickly.
Q: Can I skip the flour?
A: You can, but the filling will be looser. The teaspoon of flour is small but effective at giving the gratin a creamier, sliceable consistency.
Q: Is there a vegan version?
A: This exact recipe relies on dairy and butter for structure and flavor. A vegan version would need plant-based milk, vegan butter, and a melting dairy-free cheese — results will differ and may require recipe testing for texture.
Hungry for More?
If you liked this small gratin, try scaling the technique for a vegetable gratin with thinly sliced zucchini and tomatoes, or swap potatoes for thinly sliced sweet potatoes for a slightly sweeter side. Small pans like the 7×5 are great for testing flavor combos and feeding two without leftovers you don’t want to deal with.
Want more cozy, scaled-for-two recipes? I post simple, practical dishes that fit weeknight rhythms and small households — from single-pan mains to small-batch desserts. Try this gratin again with a different cheese or herb and see how such a small change can make it feel new.
Cheesy Potato Gratin for Two
Equipment
- 7x5-inch baking dish
- Oven
- foil or baking sheet
- Knife
- Cutting Board
Ingredients
Ingredients
- 7 x5-inch baking dish
- 1 large russet potato about12 ozthinly sliced and divided
- 1/4 onionhalved root to tip and thinly sliced
- 1/4 teaspoonsaltdivided
- 1/8 teaspoonpepperdivided
- 1 heaping teaspoonall-purpose flour
- 1 tablespooncold butterdiced and divided
- 1/2 cup 2 oz shredded Cheddar cheesedivided
- 1/3 cupmilk
- 1/3 cupheavy cream
Instructions
Instructions
- Preheat the oven to 400°F. Lightly grease the 7x5-inch baking dish.
- Thinly slice the 1 large russet potato (about 12 oz) into even slices. Divide the slices into two roughly equal piles.
- Take the 1/4 onion, halve it root-to-tip, then thinly slice the halves.
- Arrange half of the potato slices in an even layer in the prepared dish. Top the potatoes with all of the sliced onion, spreading it evenly.
- Sprinkle half of the 1/4 teaspoon salt and half of the 1/8 teaspoon pepper evenly over the onions. Sprinkle the heaping teaspoon of all-purpose flour evenly over the onions. Scatter half of the diced cold butter and sprinkle half of the shredded Cheddar over this layer.
- Add the remaining potato slices in an even layer over the first layer. Sprinkle the remaining salt and pepper, dot with the remaining diced butter, and sprinkle the remaining shredded Cheddar on top.
- Pour the 1/3 cup milk and 1/3 cup heavy cream evenly over the potatoes and cheese.
- Place a sheet of foil or a baking sheet on the oven’s bottom rack to catch any bubbling over. Put the gratin on the center rack and bake for 40 to 60 minutes, until the potatoes are fork-tender and the top is bubbly.
- Remove from the oven and let the gratin rest for five minutes before serving.
