Hard-Boiled Egg Casserole

Ingredients (10)

• + 8 hard-boiled eggs, peeled and halved add to pantry
• ✓ ¼ cup butter
• + ¼ cup all-purpose flour add to pantry
• + 2 cups half-and-half add to pantry
• + ½ teaspoon salt add to pantry
• ✓ ¼ teaspoon ground black pepper
• ✓ ¼ teaspoon garlic powder
• + ¼ teaspoon dry mustard add to pantry
• + 1 cup shredded Gruyere cheese add to pantry
• + ½ cup freshly grated Parmesan cheese add to pantry