Triple Cheese Dream Mac Cheese Seriously Good Comfort

Ingredients

• 1 pound (450g) elbow macaroni
• Water for boiling, generously salted
• 1/2 cup (113g) unsalted butter
• 1/2 cup (60g) all-purpose flour
• 3 cups (710ml) whole milk
• 1/2 teaspoon salt
• 1/4 teaspoon black pepper
• Pinch of nutmeg (optional)
• 2 cups (225g) shredded sharp cheddar cheese
• 1 cup (113g) shredded Gruyère cheese
• 1/2 cup (50g) grated Parmesan cheese
• 1/4 cup (28g) Panko breadcrumbs (optional)
• 1 tablespoon melted butter (optional)