My neighbor Doris brought this simple potato and onion bake to a church potluck one fall, and I still remember how the whole room smelled—like Sunday suppers from years ago. The pan came out of the oven with golden, blistered potatoes and sweet, caramelized onions, and before the meal was over everyone was asking her how she made it. When she said it was only three ingredients, you could hear the surprise around the table. This is the kind of practical Midwestern recipe I love: humble pantry staples, a hot oven, and a little patience that rewards you with a pan of completely fork-tender potatoes every single time.
This potato and onion bake is lovely alongside roast chicken, pork chops, or a simple meatloaf. I like to spoon the onions and their juices over the meat like a rustic gravy. It also works as a hearty base for a meatless supper with a green salad and sliced tomatoes on the side. If you’re serving it at a potluck, keep it right in the foil-lined pan; it stays warm nicely and folks can scoop it up with a big spoon. Leftovers reheat well in a skillet with a fried egg on top for breakfast or a light lunch.
3-Ingredient Potato and Onion Bake
Servings: 6

Ingredients
3 pounds russet or Yukon Gold potatoes, peeled (if desired) and thinly sliced
2 large yellow onions, thinly sliced
1/2 cup salted butter, melted (1 stick)
Directions
Preheat your oven to 400°F (200°C). Line a large rimmed baking sheet with aluminum foil, letting some foil hang over the edges for easy cleanup.
Thinly slice the potatoes into about 1/8- to 1/4-inch rounds so they cook evenly and become fork tender. Thinly slice the onions as well. Keeping the slices fairly even in thickness helps everything bake at the same rate.
Spread the sliced potatoes and onions out on the foil-lined baking sheet, tossing them together with your hands so the onions are nestled throughout the potatoes rather than sitting in one layer.
Drizzle the melted salted butter evenly over the potatoes and onions. Use clean hands or a spatula to gently toss everything right on the baking sheet until every slice looks lightly coated. Spread the mixture back into an even layer, keeping it in a fairly single, slightly overlapping layer so it can brown well.
Cover the baking sheet tightly with another sheet of foil, crimping the edges all the way around to seal in the steam. This first covered bake is what makes the potatoes turn out completely fork tender every time.
Place the pan on the center rack and bake, covered, for 35–40 minutes, until the potatoes are very tender when pierced with a fork. If your slices are on the thicker side, you may need an extra 5–10 minutes.
Carefully remove the top layer of foil (watch for steam) and gently stir the potatoes and onions to bring some of the softer pieces up from the bottom. Spread them back out into an even layer.
Return the uncovered pan to the oven and bake for another 20–25 minutes, stirring once halfway through, until the potatoes are golden in spots, the onions are deeply caramelized around the edges, and the butter has browned slightly. The potatoes should be completely fork tender and lightly crisped on the edges.
Let the pan rest for 5–10 minutes before serving so the hot butter settles and the flavors come together. Serve warm, scooping up both the potatoes and the caramelized onions from the bottom of the pan.
Variations & Tips
If you like a deeper roasted flavor, you can lower the oven to 375°F and extend the uncovered bake by 10–15 minutes, stirring once or twice, until you see lots of browning along the edges. For a creamier texture, slice the potatoes a bit thicker and keep the pan more tightly packed; they’ll steam a bit more under the foil. Yukon Gold potatoes will give you a buttery, rich bite, while russets will be a little fluffier inside with crispier edges. If you need to stretch the recipe for a big potluck, you can add an extra pound of potatoes and one more onion without changing the amount of butter; just use a very large baking sheet or two smaller ones and rotate them in the oven. To make ahead, bake covered until tender, cool, and refrigerate right in the foil-lined pan; before serving, bring to room temperature, then finish the uncovered browning step so they’re freshly caramelized and hot at the table.