# What You Need:
→ Vegetables
01 - 2 lbs Yukon Gold or Russet potatoes, peeled and thinly sliced
02 - 1 medium yellow onion, thinly sliced
→ Dairy
03 - 2 cups shredded sharp cheddar cheese
04 - 1 cup shredded mozzarella cheese
05 - 2 cups whole milk
06 - 2 tbsp unsalted butter
07 - 2 tbsp all-purpose flour
→ Seasonings
08 - 1 tsp salt
09 - 1/2 tsp black pepper
10 - 1/2 tsp garlic powder
11 - 1/4 tsp paprika
# How-To Steps:
01 - Preheat oven to 375°F. Grease a 9x13-inch baking dish with butter or cooking spray.
02 - Melt 2 tbsp butter in a medium saucepan over medium heat. Add 2 tbsp flour and whisk for 1 minute to form a roux.
03 - Slowly pour in 2 cups whole milk while whisking constantly to prevent lumps. Continue cooking until the mixture thickens slightly, approximately 3-4 minutes.
04 - Remove from heat. Stir in salt, black pepper, garlic powder, and half of the cheddar and mozzarella cheeses until fully melted and smooth.
05 - Layer half the sliced potatoes in the prepared baking dish. Top with half the onion slices, followed by half the cheese sauce. Repeat with remaining potatoes, onions, and cheese sauce.
06 - Sprinkle the remaining shredded cheeses and paprika evenly over the top layer.
07 - Cover the baking dish with aluminum foil and bake for 40 minutes.
08 - Remove foil and bake for an additional 25-30 minutes until potatoes are tender and the top reaches a golden brown color.
09 - Allow the dish to rest for 10 minutes before serving to allow the layers to set.