Found this in my aunt’s recipe box from 1958. She served these at every bridge club meeting.

This Oven-Baked 4-Ingredient Potato Au Gratin Cups recipe is a masterclass in individual-portion heat distribution and laminar starch saturation. By utilizing a standard 12-cup muffin tin, you increase the surface-area-to-volume ratio, allowing the heavy cream and minced yellow onion to reduce more rapidly than in a traditional casserole dish. The two-stage cheddar cheese application creates a “dual-crust” architecture: a lacy, fried-cheese base and a soft, golden-brown “fat-cap” that locks in the moisture of the thinly sliced russet potatoes.

Oven-Baked 4-Ingredient Potato Au Gratin Cups

Ingredients:

Step-by-Step Directions:

Step 1: The Precision Slice: Preheat oven to 375°F. Peel and slice the potatoes to 1/8-inch thickness. Grease a 12-cup muffin tin thoroughly.

Tip: Using Russet potatoes is a structural necessity. Russets have the highest starch content, which leaches into the heavy cream to create a thick, stable sauce. If you use a waxy potato (like Red Bliss), the cups may remain “watery” and lose their shape when removed from the tin.

Step 2: The Aromatic Cream: Whisk together the heavy cream, minced onion, salt, and pepper.

Tip: Mincing the onion very finely is a vital mechanical step. Because these cups are small and cook relatively quickly, larger onion chunks would remain crunchy and release too much water, potentially “breaking” the cream emulsion. Fine mincing ensures the onion melts into the sauce, providing a savory backbone without textural interference.

Step 3: The Base “Lace”: Distribute 1 cup of the cheese into the bottoms of the 12 cups.

Tip: Placing cheese at the bottom is a chemical necessity. As the heat radiates from the bottom of the tin, this cheese undergoes a “frico” transformation—frying in the potato starches and cream to create a sturdy, savory base that allows you to lift the cups out in one piece.

Step 4: The Layered Assembly: Stack the potato slices to the top of each cup. Spoon the cream mixture over the stacks and top with the remaining 1 cup of cheese.

Note: Pour the cream slowly; you want it to “wick” down through the layers via capillary action rather than pooling on top.

Step 5: The Thermal Bake: Place the tin on a rimmed baking sheet (to catch drips) and bake for 35/45 minutes.

Note: The cups are ready when a knife slides through the center with zero resistance and the tops are a deep, “bridge club” golden-brown.

Step 6: The “Set” Rest: Let the cups rest in the tin for 10 minutes before removing.

Tip: This rest is a “viscosity” necessity. The cream is at its most fluid state when boiling. Cooling for ten minutes allows the starches to fully “re-link,” turning the liquid into a solid, spoonable custard that holds the potato slices together.