Cheesy potato casserole is the side dish that disappears first at every holiday table and potluck. Shredded potatoes are folded into a creamy cheddar sauce, then topped with something buttery and crunchy and baked until bubbling. This version makes the sauce from scratch, which tastes fresher than canned soup and gives you control over the salt.
Serves: 10 as a side. Prep: 20 minutes. Bake: 45 to 50 minutes.
Ingredients
For the casserole
- 1 bag (30 ounces / 850 g) frozen shredded hash browns, thawed
- 3 tablespoons butter
- 1 small onion, finely diced
- 3 tablespoons all-purpose flour
- 1½ cups (360 ml) whole milk
- 2 cups (8 ounces / 225 g) shredded sharp cheddar, divided
- 1 cup (240 g) sour cream
- 1 teaspoon salt
- ½ teaspoon black pepper
- ½ teaspoon garlic powder
- 3 green onions, sliced
For the topping
- 2 cups (about 60 g) crushed cornflakes or buttery crackers
- 4 tablespoons butter, melted
Instructions
- Heat the oven to 350°F (175°C) and grease a 9×13-inch baking dish.
- Melt the butter in a large saucepan over medium heat. Cook the onion for 4 to 5 minutes until soft.
- Whisk in the flour and cook for 1 minute. Slowly whisk in the milk and simmer, stirring, for 3 to 4 minutes until thick enough to coat a spoon.
- Remove from the heat. Stir in 1½ cups of the cheese until melted, then the sour cream, salt, pepper and garlic powder.
- Fold in the thawed hash browns and green onions until evenly coated.
- Spread the mixture in the dish and sprinkle with the remaining ½ cup cheese.
- Toss the crushed cornflakes with the melted butter and scatter over the top.
- Bake for 45 to 50 minutes, until the edges bubble and the topping is deep golden. Rest for 10 minutes before serving.
Keys to a creamy, not greasy, casserole
- Thaw the potatoes fully. Frozen hash browns bring a lot of ice, and that melts into a watery sauce. Leave the bag in the fridge overnight, then press the potatoes lightly between paper towels.
- Shred your own cheese. Pre-shredded cheese is coated to prevent clumping, and it can make the sauce grainy. A block melts more smoothly.
- Take the sauce off the heat before adding cheese and sour cream. Direct heat can make dairy separate and turn oily.
- Use sharp cheddar. Mild cheese disappears in a dish this rich.
If your sauce comes out thinner than you expected, our guide to thickening soups, stews and sauces has simple fixes.
Using fresh potatoes
You can skip the bag. Peel 2½ pounds (1.1 kg) of russet or Yukon Gold potatoes and shred them on the large holes of a box grater. Rinse in cold water until it runs mostly clear, then wring them out in a clean dish towel. This step matters, because shredded raw potato holds a lot of water and starch. Cook the shredded potatoes in the microwave or a skillet for a few minutes first, or add 10 to 15 minutes to the bake. Season well, since potatoes absorb a lot of salt. For help choosing salt, see our kosher, sea or table salt guide.
Topping ideas
- Cornflakes and butter: the classic. It stays crisp for a long time.
- Crushed buttery crackers: richer and slightly salty.
- Panko with Parmesan: light and crunchy. Toss with butter and a pinch of paprika.
- Crispy fried onions: savory and a bit nostalgic.
- Extra cheese only: skip the crunch and bake until browned.
Variations
- Bacon: fold in 6 slices of crumbled cooked bacon. Our BLT guide has tips for getting bacon crisp.
- Ham: add 1½ cups diced ham to turn it into a main dish.
- Jalapeño: add 2 diced fresh jalapeños or a small can of green chiles, and use pepper Jack in place of half the cheddar. For heat control, see how to make jalapeños mild, medium or hot.
- Broccoli: fold in 2 cups of blanched, chopped broccoli.
- Lighter version: use Greek yogurt in place of sour cream and a little less cheese. The sauce will be slightly tangier.
Make ahead, freeze and reheat
Assemble the casserole through step 6 up to a day ahead, cover and refrigerate, but keep the topping separate so it stays crunchy. Add the topping just before baking and add 10 minutes to the time. To freeze, wrap the unbaked casserole (no topping) tightly and freeze for up to three months. Thaw overnight in the fridge before baking. More guidance on what holds up is in our freezer-friendly meals guide. Leftovers keep for three to four days, and reheat in a 350°F (175°C) oven covered with foil until hot throughout, then uncovered for a few minutes to recrisp the top.
Serving ideas
This casserole is a natural partner for roasted or grilled meat. Serve it alongside baked chicken thighs and a green vegetable, or add it to a holiday spread. If you are juggling a crowded menu, our guide to cooking a big meal with one oven shows how to schedule it, since this casserole reheats well and can bake while the main dish rests. More ideas are in our holiday meal ideas. For a hearty main-dish alternative, try our hamburger casserole with potatoes.
Common questions
Why is my casserole watery? The potatoes were not fully thawed or drained, or the sauce was too thin. Thaw overnight and simmer the sauce until it coats a spoon.
Why is it greasy? The sauce got too hot after the cheese went in, or the cheese was low quality. Take the pan off the heat first.
Can I make it in a slow cooker? Yes. Combine everything except the topping and cook on low for 4 to 5 hours, then add the topping separately in the oven or skillet for crunch.
Can I use canned soup? Yes. Replace the butter, flour and milk with one 10.5-ounce can of cream of chicken soup, but the sauce will taste more processed.
