makes 6 large servings
4 tablespoons (1/2 stick) unsalted butter, plus more for buttering your casserole dish
3 slices white bread, crusts removed, cut into 1/4" cubes
2 3/4 cups skim milk
1/4 cup all-purpose flour
1 teaspoon kosher salt, plus more for water
1/8 teaspoon ground nutmeg
1/8 teaspoon freshly ground black pepper
1/8 teaspoon cayenne pepper
2 1/4 cups grated sharp white cheddar cheese
1/2 cup (about 8 ounces) grated Gruyère
1/4 cup Pecorino Romano
1/2 lb elbow macaroni
1. Preheat the oven to 375 degrees. Butter a 1.5-quart casserole dish. Set aside.
2. Melt 1 tablespoon of butter in a small saucepot. Place the bread cubes into a medium bowl. Pour the melted butter over the bread cubes and toss to coat. Set aside.
3. Warm the milk over medium heat in a medium-sized saucepot. At the same time, melt the remaining 3 tablespoons of butter in a high-walled skillet. When the butter starts to sizzle and bubble, add the flour and whisk to combine.
4. Add the warmed milk to the butter-flour mixture. Continue whisking briskly to combine the ingredients into a smooth liquid. Continue cooking (and whisking) for 8-10 minutes, or until the mixture begins to thicken. Once the mixture begins to thicken, remove the skillet from the heat.
5. Stir in the salt, nutmeg, black pepper, cayenne pepper, 1.5 cups of grated sharp cheddar, and 1/4 cup of grated Gruyère. Once combined, set aside.
6. Bring a large pot of water to a boil. Season liberally with salt. Add in the half-pound of elbow macaroni and cook for 1-2 minutes less than the instructions indicate.
7. Once cooked, drain the macaroni and rinse it under cold water.
8. Add the cooked macaroni to the cheese sauce and stir to combine.
9. Spoon the macaroni and cheese into the prepared casserole dish. Sprinkle the top with the remaining 3/4 cup of cheddar cheese, 1/4 cup of Gruyère, and 1/4 cup of Pecorino Romano. Add the buttered bread cubes evenly over the top of the cheese.
10. Bake in the oven for 25-30 minutes, or until the cheese is bubbly and the bread cubes are lightly toasted. Cool for five minutes on a wire rack before serving.