This is my streamlined version of a scalloped potato recipe I found in my mom’s old recipe box, handwritten on a yellowed card dated 1942. She baked it for every single holiday—Easter, Thanksgiving, Christmas—right up until the year she passed, and the smell of it in the oven still takes me right back to her crowded little kitchen. It’s just four ingredients, nothing fancy, but it comes out with tender layers of potatoes, a simple creamy sauce that bubbles up around the edges, and a golden, crispy top. It’s the kind of dish you make when you’re juggling work, kids, and a busy schedule, but still want something that feels like it’s been on the table for generations.
These scalloped potatoes are rich and comforting, so I like to balance them with something simple and a little lighter on the side—think roasted green beans, a crisp green salad, or steamed broccoli. They’re perfect next to classic holiday mains like roast turkey, ham, or pot roast, but they also work on a regular weeknight with baked chicken or pork chops. If you’re serving a crowd, keep the potatoes in the turned-off oven (door slightly cracked) while you finish the rest of the meal; they hold well and the top stays nicely golden.
Oven Baked 4-Ingredients Scalloped Potatoes
Servings: 6
Ingredients
2 tablespoons unsalted butter, softened (for greasing the dish and dotting on top)
2 pounds russet or Yukon Gold potatoes, peeled and thinly sliced (about 1/8 inch thick)
1 medium yellow onion, very thinly sliced
2 cups whole milk
1 teaspoon kosher salt (or to taste)
1/2 teaspoon freshly ground black pepper (or to taste
Directions
Preheat your oven to 375°F (190°C). Lightly grease a rectangular glass baking dish (about 9x13 inches or similar) with a little of the softened butter, making sure to coat the bottom and sides so the potatoes don’t stick.
Peel the potatoes and slice them as thinly and evenly as you can, about 1/8 inch thick. A sharp knife works fine; if you have a mandoline, this is a good time to use it. Thin slices help the potatoes cook through and get that tender, layered texture.
Peel and very thinly slice the onion into half-moons or rings. The onion will almost melt into the potatoes as they bake, giving that classic old-fashioned flavor without needing extra seasonings.
Layer about one-third of the sliced potatoes in the bottom of the prepared baking dish, spreading them out in an even, slightly overlapping layer. Scatter one-third of the sliced onions over the potatoes. Sprinkle lightly with some of the salt and pepper.
Repeat the layers two more times: another third of the potatoes, a third of the onions, and a light sprinkle of salt and pepper each time, finishing with a top layer of potatoes and onions. Try to keep the top layer fairly neat and overlapping so it browns nicely.
Pour the milk evenly over the layered potatoes and onions, tilting the dish gently if needed so the milk settles down between the layers. You want the milk to come about halfway to two-thirds of the way up the potatoes, not completely covering them.
Dot the top with the remaining softened butter, breaking it into small pieces and scattering them across the surface. This helps the top get those golden, crispy edges that make the dish look so inviting in the pan.
Cover the baking dish tightly with foil and place it on the middle rack of the preheated oven. Bake for 45 minutes, until the potatoes are starting to soften and the milk is hot and just beginning to bubble around the edges.
Remove the foil and continue baking, uncovered, for another 30–40 minutes, or until the potatoes are very tender when pierced with a knife and the top is bubbly and golden brown with some crispy edges. If the top is browning too quickly before the potatoes are tender, loosely re-cover with foil for part of the remaining time.
Once done, remove the dish from the oven and let the scalloped potatoes rest for at least 10–15 minutes before serving. The sauce will thicken slightly as it cools, and the layers will hold together better when you scoop it out. Serve straight from the glass baking dish at the table, just like it would have been done in 1942.
Variations & Tips
To keep the spirit of the original 1940s recipe but adapt it to modern life, you can make a few simple tweaks. For extra richness, replace up to 1/2 cup of the milk with heavy cream or evaporated milk—this keeps the ingredient list short but makes the sauce thicker and more indulgent. If you’re trying to get ahead on a busy holiday, assemble the dish a few hours in advance, cover, and refrigerate; let it sit on the counter for 20–30 minutes while the oven heats, then bake as directed, adding 10–15 minutes if needed. For a slightly smokier flavor that still feels old-fashioned, you can tuck a few very thin slices of cooked ham between the potato layers. If you like a bit more color, sprinkle a pinch of paprika over the top before baking. To stretch the recipe for a larger crowd, use a bigger baking dish and increase all ingredients by 50%, baking a little longer until the center is tender. Leftovers reheat well covered in the oven at 325°F; add a splash of milk if they seem dry, then warm until bubbly.