This little 5-ingredient oven baked potato dish is the kind of thing Midwestern grandmas have been pulling out of their ovens for generations. It starts with plain raw russet potatoes, sliced thin and laid right into a glass baking dish, then dressed with just four pantry staples you probably have on hand. No fussing with parboiling or fancy cheeses—just simple ingredients, slow baking, and that cozy, creamy potato comfort that makes everyone reach for seconds. It reminds me of the kind of side dish that showed up at every church potluck and harvest supper when I was growing up, humble but always scraped clean by the end of the meal.
This dish is at home next to just about any hearty main: Sunday roast, baked ham, meatloaf, or simple pan-fried pork chops. It also pairs nicely with grilled chicken or sausages when you want the oven to do the work for the side. Add a green vegetable—steamed green beans, buttered peas, or a crisp salad with a tangy dressing—to balance the richness. Leftovers warm up beautifully and can be served alongside eggs for breakfast or tucked next to a slice of leftover meat for an easy lunch.
5-Ingredient Baked Russet Potato CasseroleServings: 6
Ingredients
2 1/2 pounds russet potatoes, scrubbed and very thinly sliced (about 1/8 inch)
3 cups whole milk
4 tablespoons unsalted butter, cut into small pieces, plus extra for greasing the dish
2 teaspoons kosher salt
1 teaspoon black pepper
Directions
Preheat your oven to 375°F (190°C). Generously butter a 9x13-inch glass baking dish, making sure to get into the corners so the potatoes don’t stick.
Scrub the russet potatoes well and pat them dry. Leave the skins on for a more rustic, old-fashioned feel, or peel them if you prefer. Using a sharp knife or mandoline, slice the potatoes into very thin rounds, about 1/8 inch thick. The thinner they are, the creamier and more tender the dish will be.
Spread about one-third of the raw potato slices in an even layer across the bottom of the buttered glass baking dish. It’s fine if they overlap; just try to keep the layer fairly even so they cook at the same rate.
Sprinkle about one-third of the salt and pepper evenly over this first layer of potatoes. Dot the top with roughly one-third of the butter pieces.
Repeat with a second and third layer: arrange another third of the potatoes, season with another third of the salt and pepper, and dot with another third of the butter each time, finishing with the last of the butter on top.
Slowly pour the milk over the potatoes, aiming to distribute it evenly so it seeps down between the slices. The liquid should come just below the top layer of potatoes; if your dish is a bit larger or your potatoes are piled higher, add a splash more milk so the layers are mostly surrounded by liquid without overflowing the dish.
Cover the glass baking dish tightly with aluminum foil. Place the dish on a rimmed baking sheet in case of any bubbling over, then slide it into the preheated oven.
Bake covered for 45–55 minutes, until the potatoes are starting to turn tender when pierced with the tip of a knife and the milk is hot and steamy. Carefully remove the foil, watching out for the burst of steam.
Return the uncovered dish to the oven and continue baking for another 25–35 minutes, until the potatoes are completely tender, the top is lightly browned in spots, and the milk and butter have thickened into a creamy sauce. If the top is browning too quickly before the potatoes are fully tender, lay the foil back over loosely and continue baking until done.
Once finished, remove the dish from the oven and let it rest for at least 10–15 minutes before serving. This short rest helps the creamy juices settle and thicken so every scoop holds together nicely. Serve warm, straight from the glass baking dish, and don’t be surprised if your family scrapes up every last bit from the corners.
Variations & Tips
For a little extra richness, you can swap 1 cup of the milk for heavy cream, but keep the total liquid to about 3 cups so the potatoes don’t turn soupy. If you like a more golden top, dot an extra tablespoon of butter over the last 10 minutes of baking, or slide the dish under the broiler for a minute or two, watching closely so it doesn’t burn. A pinch of garlic powder or onion powder mixed with the salt and pepper will give this a flavor similar to old-fashioned boxed scalloped potatoes, while still keeping the ingredients simple. You can also tuck in very thin slices of onion between the layers if that’s something your family enjoys, though it will add another ingredient beyond the basic five. For a smaller household, halve the recipe and bake it in an 8x8-inch glass dish, checking for doneness a bit earlier. Food safety tips: Always start with clean, scrubbed potatoes, trimming off any green spots or deep eyes. Keep the sliced potatoes refrigerated if you need to pause before assembling; don’t leave raw, sliced potatoes sitting at room temperature for more than 1–2 hours. Make sure the casserole is heated through and bubbling before serving so the milk has reached a safe temperature. Cool leftovers promptly within 2 hours, store them tightly covered in the refrigerator, and enjoy within 3–4 days, reheating until hot all the way through.
