INGREDIENTS :
1 pound elbow macaroni
6 slices white bread, cut into 1/4-inch pieces
1/2 cup (1 stick) unsalted butter, divided
5 1/2 cups whole milk, warmed
4 1/2 cups sharp white cheddar cheese, grated, divided
2 cups gruyere cheese, grated, divided
1/2 cup all-purpose flour
2 teaspoons kosher salt
1/4 teaspoon ground black pepper
1/4 teaspoon ground nutmeg
1/4 teaspoon cayenne pepper
PREPARATION :
Bring a large pot of salted water to boil and cook macaroni for 1-2 minutes less than instructed on packaging. There should still be a bit of bite to the pasta. Rinse with cold water, then drain and set aside.
Preheat oven to 375º F and lightly grease a 9×13-inch baking dish with butter or non-stick spray. Toss bread cubes with 2 tablespoons melted butter in a medium bowl and set aside.
In a large saucepan over medium heat melt remaining butter (6 tablespoons) until bubbly, then stir in flour. Cook, stirring frequently, for 1 minute.
While whisking, pour in warmed milk until fully incorporated. Continue whisking until mixture thickens and bubbles up.
Remove from heat and season with salt, pepper, nutmeg and cayenne, then stir in 3 cups cheddar cheese and 1 1/2 cups gruyere.
Stir drained pasta into cheese sauce, then transfer to greased baking dish. Top with remaining cheddar and gruyere cheese, then sprinkle buttered breadcrumbs on top.
Place in oven and bake for 25-30 minutes, or until golden brown on top.
Remove from oven and serve hot!