CHEESY SCALLOPED POTATOES

Name: CHEESY SCALLOPED POTATOES
Prep time: 30 min
Cook time: 40 min
Total time: 1 h 10 min
Cuisine: American
Ingredients: 4 large russet potatoes, thinly sliced; 2 cups sharp cheddar cheese, shredded; 1 cup Gruyère cheese, shredded; 4 tablespoons unsalted butter; 1/4 cup all-purpose flour; 2 cups whole milk, warmed; 2 cloves garlic, minced; 1 teaspoon Dijon mustard; Salt and black pepper to taste; 1/2 teaspoon nutmeg (optional, for a warm flavor)