These oven baked 5-ingredient Amish cheesy au gratin potatoes are my go-to comfort side when life is busy but I still want something that tastes like it simmered on Grandma’s stove all afternoon. My Amish neighbor down the road showed me how she layers simple pantry staples—potatoes, cream, cheese, butter, and onion—into the creamiest, bubbliest pan of potatoes I’ve ever had. There’s no fussy roux or long ingredient list, just honest, rich flavors that bake together into a golden casserole my family now begs for on repeat weeknights and holidays alike.
These potatoes are rich and comforting, so I like to balance them with something simple and protein-forward: roast chicken, grilled pork chops, or a pan-seared steak all pair beautifully. For a lighter plate, serve with a big green salad tossed in a tangy vinaigrette or some steamed green beans. They’re also perfect on a holiday table alongside ham and roasted vegetables, and the leftovers reheat well for an easy lunch with a fried egg on top.
Oven Baked Amish Cheesy Au Gratin Potatoes
Servings: 6
Ingredients
3 pounds russet or Yukon Gold potatoes, peeled and very thinly sliced
1 medium yellow onion, very thinly sliced
2 cups heavy cream
3 cups shredded sharp cheddar cheese, divided
4 tablespoons unsalted butter, cut into small pieces
1 teaspoon kosher salt
1/2 teaspoon black pepper
Nonstick cooking spray or a little extra butter, for greasing the dish
Directions
Preheat your oven to 375°F (190°C). Lightly grease a 9x13-inch or similar-sized white oval casserole dish with nonstick spray or a little butter so the potatoes don’t stick.
Peel the potatoes and slice them very thinly, about 1/8 inch thick. The thinner the slices, the creamier and more melded the final dish will be. Slice the onion thinly as well so it softens and almost melts into the sauce as it bakes.
In a medium bowl or large measuring cup, whisk together the heavy cream, salt, and black pepper. This simple seasoned cream is the secret to that rich, velvety sauce—no flour or canned soup needed.
Spread a thin, even layer of potato slices over the bottom of the prepared casserole dish, slightly overlapping the slices like shingles. Scatter a few onion slices over the potatoes, then sprinkle with a small handful of shredded cheddar cheese and a few pieces of butter.
Repeat the layering: potatoes, onion, cheddar, and butter, building up until you’ve used all the potatoes and onions. Reserve about 1 cup of the shredded cheese for the very top so you get that golden, bubbly crust.
Slowly pour the seasoned cream evenly over the layered potatoes, tilting the dish gently if needed to help the cream work its way down between the layers. The cream should come almost to the top layer but not completely cover it.
Sprinkle the reserved 1 cup of cheddar cheese evenly over the top layer of potatoes. This will create that browned, cheesy top you see in the photo once it bakes.
Cover the casserole tightly with foil and bake in the preheated oven for 45 minutes. Covering the dish lets the potatoes steam and turn tender while the cream thickens into a sauce.
After 45 minutes, carefully remove the foil and continue baking, uncovered, for another 25–35 minutes, or until the potatoes are very tender when pierced with a knife and the top is deeply golden and bubbly. If the top is browning too quickly, you can loosely tent it with foil again.
Once baked, let the potatoes rest on the counter for at least 10–15 minutes before serving. This short rest helps the creamy cheese sauce thicken slightly so you get those perfect, scoopable slices of potatoes in rich cheese sauce, just like in the picture.
Serve warm straight from the casserole dish. The edges will be extra caramelized and cheesy, so don’t forget to scrape those bits—they’re always the first to disappear at my table.
Variations & Tips
To save time on busy weeknights, you can slice the potatoes and onion up to a day ahead and store them in cold water in the fridge, then drain and pat dry before layering. For extra depth, swap half of the cheddar for smoked cheddar or Swiss cheese. If you like a little garlic, rub a cut clove of garlic around the inside of the baking dish before greasing it, or add 1/2 teaspoon of garlic powder to the cream. For a slightly lighter version, use half-and-half instead of heavy cream and reduce the butter to 2 tablespoons, knowing the sauce will be a bit less rich but still delicious. You can also make this ahead: assemble the casserole, cover, and refrigerate up to 24 hours, then bake an extra 10–15 minutes to account for starting from cold. Leftovers reheat well covered in the oven at 325°F or in the microwave with a splash of cream to bring back the silkiness.