1-Diving into this Scalloped Potatoes Recipe is simpler than you might think, and we’ll walk you through each step. Start by preheating your oven to 400°F and lightly spraying an 8×8-inch casserole dish with nonstick cooking spray. This sets the stage for even baking and helps everything come out just right.

2-Next, arrange the potatoes and onions in the dish by alternating layers for that classic look and flavor. In a saucepan over medium heat, melt the 3 tablespoons of butter, then whisk in the 3 tablespoons of all-purpose flour and ½ teaspoon kosher salt; cook for 1 minute to build a smooth base.

3-Gradually stir in the 2 cups of whole milk and cook until the mixture thickens, creating a creamy sauce. Add the 1 ½ cups of shredded cheddar cheese all at once, stirring until it’s melted and smooth for that cheesy goodness.

4-First Steps: Prepping and Layering Begin with preheating the oven and slicing your ingredients. Layer the potatoes and onions carefully in the dish for even cooking.

5-Cooking the Sauce Melt the butter and mix in flour and salt. Add milk slowly and cook until thick, then stir in cheese for a rich finish.

6-Baking to Perfection Pour the sauce over the layers, cover with aluminum foil, and bake for 85-90 minutes until tender. For a crispier top, broil briefly after baking and season with salt and pepper before serving.