This Cheesy Potato Casserole is a lightened-up version of the beloved Midwest classic. With a creamy base made from Greek yogurt and sour cream, plus a golden, crunchy cornflake topping, this dish is hearty, flavorful, and satisfying. Perfect as a side for family dinners, holiday feasts, or potlucks, it’s a crowd-pleaser that also happens to be vegetarian and gluten-free friendly when using the right substitutions.

Cheesy Potato Casserole

Why You’ll Love This Recipe

Creamy, cheesy, and comforting with a lighter twist.
A great make-ahead side dish for holidays and gatherings.
Uses simple, everyday ingredients.
Gluten-free friendly with the right flour and cereal substitutions.
Perfectly crispy topping for added texture.

Ingredients

(Tip: You’ll find the full list of ingredients and measurements in the recipe card below.)

6 tablespoons butter, divided
3 tablespoons flour (1:1 gluten-free all-purpose may be used)
1/2 teaspoon onion powder
1/4 teaspoon garlic powder
1/2 teaspoon fine sea salt
1/2 teaspoon black pepper
1 ¾ cups milk of choice (e.g., unsweetened plain cashew milk)
3/4 cup plain Greek yogurt
3/4 cup sour cream
1 pound (32 ounces) packaged diced potatoes, thawed
1 cup shredded Monterey Jack or cheddar cheese
1 cup cubed sharp cheddar cheese
2 cups corn flakes cereal

Directions

Preheat oven to 350ºF and lightly grease a 9×13-inch baking dish with butter.
In a medium saucepan over medium-high heat, melt 4 tablespoons butter. Whisk in the flour, onion powder, garlic powder, salt, and pepper. Cook for about 2 minutes until bubbling.
Slowly whisk in the milk, stirring continuously for 4–5 minutes until thickened. Remove from heat.
In the prepared baking dish, add the thawed diced potatoes. Pour in the sauce mixture, then add Greek yogurt, sour cream, shredded cheese, and cubed cheese. Stir to combine.
Bake uncovered for 45 minutes.
In the last 5 minutes of baking, melt the remaining 2 tablespoons butter and toss with corn flakes.
Remove the casserole, top with corn flakes and extra shredded cheese if desired. Return to oven for 15 more minutes.
Optional: Broil for the last 3–4 minutes for a crisp, golden top.
Let stand for 15 minutes before serving.

Servings and timing

Servings: 12 servings
Prep time: 10 minutes
Cook time: 1 hour
Total time: 1 hour 10 minutes
Calories: 278 kcal per serving (approx.)

Variations

Use all shredded cheese instead of cubed for a smoother texture.
Try different cheeses such as Gruyère, Fontina, or Colby Jack.
Substitute plain yogurt for Greek yogurt if you prefer a lighter flavor.
Use gluten-free corn flakes and flour for a completely gluten-free version.
Add sautéed vegetables like mushrooms, spinach, or bell peppers for more flavor.

Storage/Reheating

Store leftovers in an airtight container in the refrigerator for up to 4 days.
To reheat, warm individual portions in the microwave or reheat the whole casserole in the oven at 350ºF until hot.
Freeze before baking for up to 2 months. When ready to serve, thaw overnight in the fridge and bake as directed.

FAQs

Can I make this casserole ahead of time?

Yes, assemble it up to the baking step, cover, and refrigerate for up to 24 hours before baking.

Can I use fresh potatoes instead of frozen diced potatoes?

Yes, but they should be parboiled or partially cooked first for even baking.

What cheese works best for this casserole?

A mix of cheddar and Monterey Jack creates a creamy and flavorful dish, but you can experiment with others.

Can I make this dish completely gluten-free?

Yes, just use gluten-free flour and gluten-free corn flakes.

How do I keep the casserole from being watery?

Make sure your sauce is thickened properly before adding it to the potatoes, and thaw frozen potatoes completely.

Can I freeze leftovers?

Yes, cooked casserole can be frozen in airtight containers for up to 2 months. Thaw and reheat in the oven.

What’s the best way to reheat without losing crispiness?

Reheat in the oven at 350ºF for 15–20 minutes to keep the topping crunchy.

Can I replace the sour cream with something else?

Yes, plain Greek yogurt or cream cheese can be used as a substitute.

How can I make it lower in calories?

Use reduced-fat cheese, light sour cream, and yogurt to cut down on calories.

Can I add protein to this dish?

Yes, cooked chicken or turkey can be stirred in before baking for a heartier version.

Conclusion

Cheesy Potato Casserole is the ultimate comfort food side dish with a lighter, modern twist. Creamy, cheesy, and topped with a golden crunch, it’s a versatile recipe that works for both special occasions and weeknight dinners. Whether you keep it classic or add your own spin, this casserole is guaranteed to please.

Emma