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

This 4-Ingredient Potato Au Gratin Cups recipe is a masterclass in vertical starch-lamination and localized lipid-confinement. By utilizing a muffin tin as a series of individual pressure vessels, you facilitate hydrothermal poaching of the russet potato slices within a heavy cream matrix. The finely minced onion provides a vital aromatic infusion that breaks down during the 375°F bake, while the shredded cheddar serves two functional purposes: a “lacy” structural base and a Maillard-crusted thermal seal on top.

Oven-Baked 4-Ingredient Potato Au Gratin Cups

Ingredients:

Step-by-Step Directions:

Step 1: The Starch Prep: Preheat oven to 375°F. Grease a 12-cup muffin tin. Slice the peeled potatoes into 1/8-inch rounds (or thinner).

Tip: Slicing the potatoes to a consistent 1/8-inch thickness is a vital mechanical step. Uniformity ensures that every slice in the stack reaches its “gelatinization point” at the same time, preventing a “raw-center” texture in the middle of the cup.

Step 2: The Base Seal: Distribute 1 cup of the cheddar into the bottom of the muffin cups.

Tip: Placing cheese at the bottom is a structural necessity. As the cheese melts against the hot metal, it undergoes lipid-separation and browning, creating a crisp “cradle” that allows you to lift the entire potato stack out of the tin without it falling apart.

Step 3: The Laminar Stack: Layer the potato slices into the cups, pressing down firmly to eliminate air pockets.

Note: Fill the cups just to the top edge. As the potatoes lose moisture during the bake, the stack will shrink slightly, leaving room for the bubbling cheese and cream.

Step 4: The Cream Infusion: Whisk the cream, onion, salt, and pepper. Carefully spoon the mixture over the potatoes in each cup. Top with the remaining 1 cup of cheese.

Note: Pour slowly. You want the cream to seep through the laminar layers via capillary action rather than overflowing the pan.

Step 5: The Thermal Set & Rest: Bake for 35/45 minutes on a rimmed baking sheet. Let the cups rest in the tin for 10 minutes before removing.

Tip: This rest is a “viscosity” necessity. The cream and potato starches need those 10 minutes to form a composite bond. If you remove them too early, the internal cream will be too fluid, and your “cups” will collapse into a pile of loose slices.