This 6-ingredient oven baked potato casserole leans on a very Midwestern approach: simple pantry staples, minimal prep, and a comforting, golden-topped dish that can slide onto the table any night of the week. Instead of parboiling or fussing with a sauce on the stove, you pour raw cubed yellow potatoes straight into the casserole dish, add just five more ingredients, and let the oven do the work. The result is a creamy, cheesy, crisp-edged bake that tastes like a cross between scalloped potatoes and a diner-style hash brown casserole—exactly the kind of thing friends will ask you to bring (and then ask you for the recipe).
Serve this potato casserole hot, straight from the oven, with a simple green salad or steamed green beans to balance the richness. It’s excellent alongside roast chicken, baked salmon, or grilled sausages, and it also works as a hearty brunch dish next to scrambled eggs and fruit. Leftovers reheat well and can be topped with a fried egg and a spoonful of salsa or hot sauce for an easy next-day meal.
6-Ingredient Oven Baked Potato Casserole
Servings: 6
Ingredients
2 1/2 pounds yellow potatoes, scrubbed and cut into 1/2-inch cubes (leave skins on if thin)
1 1/2 cups shredded sharp cheddar cheese, divided
1 1/2 cups whole milk (or 2% milk)
1 cup sour cream
1 teaspoon fine sea salt (plus more to taste)
1/2 teaspoon freshly ground black pepper (plus more to taste
1 tablespoon neutral oil or softened butter, for greasing the casserole dish (optional but recommended)
Directions
Preheat your oven to 375°F (190°C). Lightly grease a 9x13-inch oven-safe casserole dish with the neutral oil or softened butter so the potatoes release easily and the edges brown nicely.
Scrub the yellow potatoes well and pat them dry. Cut them into roughly 1/2-inch cubes, aiming for even size so they cook at the same rate. There’s no need to peel if the skins are thin and smooth.
Pour the raw cubed potatoes directly into the prepared casserole dish, spreading them into an even layer. This is your base—no parboiling or pre-cooking required.
In a medium bowl, whisk together the milk, sour cream, salt, and pepper until the mixture is smooth and no streaks of sour cream remain. This simple mixture will thicken into a creamy sauce as it bakes around the potatoes.
Pour the milk and sour cream mixture evenly over the potatoes in the casserole dish, using a spatula or spoon to gently nudge the potatoes so the liquid seeps down through the cubes.
Sprinkle 1 cup of the shredded cheddar cheese evenly over the top of the potatoes, reserving the remaining 1/2 cup for later. The first layer of cheese will melt into the sauce and help it thicken and cling to the potatoes.
Cover the casserole tightly with foil, making sure it is sealed at the edges to trap steam. Transfer the dish to the preheated oven and bake for 45 minutes, until the potatoes are beginning to soften when pierced with the tip of a knife.
Carefully remove the foil (watch for hot steam), sprinkle the remaining 1/2 cup cheddar cheese evenly over the top, and return the casserole to the oven uncovered.
Continue baking, uncovered, for 20 to 30 minutes, or until the potatoes are tender all the way through, the sauce is bubbling, and the top is golden and lightly crisp at the edges. If the top is browning too quickly before the potatoes are fully tender, loosely tent with foil for the last 5 to 10 minutes.
Remove the casserole from the oven and let it rest for at least 10 minutes before serving. This resting time allows the sauce to thicken slightly and makes it easier to scoop neat portions. Taste and add a little more salt and pepper at the table if desired, then serve warm.
Variations & Tips
You can take this basic 6-ingredient framework in several directions while keeping the method the same. For extra savoriness, stir 1 to 2 teaspoons of garlic powder or onion powder into the milk and sour cream mixture before pouring it over the potatoes. If you’d like a little tang and color, scatter 2 to 3 tablespoons of chopped fresh chives or green onions over the casserole right after baking. To make it heartier, you can fold in 1 to 1 1/2 cups of cooked, crumbled bacon or diced ham with the raw potatoes in the dish before adding the liquid. For a smokier, bistro-style flavor, swap half of the cheddar for smoked cheddar or Gruyère. If you prefer a slightly lighter version, use light sour cream and 2% milk, understanding the sauce will be a touch less rich but still comforting. For a crisper top, finish the casserole under the broiler for 1 to 2 minutes, watching closely so the cheese does not burn. Food safety tips: Because you’re starting with raw potatoes and a dairy-based sauce, bake the casserole until the center is bubbling and the potatoes are fully tender—an instant-read thermometer inserted into the middle should read at least 190°F (88°C). Do not leave the unbaked casserole sitting at room temperature for more than 30 minutes; assemble it just before it goes into the oven or refrigerate immediately if you need to hold it, then add a few extra minutes to the baking time if starting from cold. Refrigerate leftovers within 2 hours of baking, store tightly covered, and use within 3 to 4 days. Reheat portions until steaming hot all the way through before serving.