Adapted from Martha Stewart Living Cookbook: The Original Classics featured on Smitten Kitchen., including tweaks with the cheese from other sources.
8 tablespoons (1 stick) unsalted butter, plus more for casserole
6 slices white bread, crusts removed. Pulse in food processor for fine crumbs.
5 1/2 cups 2% Milk
1/2 cup all-purpose flour
2 teaspoons coarse salt, plus more for water
1/4 teaspoon freshly ground nutmeg
1/4 teaspoon cayenne pepper
1/2 teaspoon freshly ground black pepper
4 1/2 cups (about 18 ounces) grated sharp white cheddar cheese (reserve 1 1/2 cup for topping)
2 cups (about 8 ounces) grated Gruyere cheese (reserve 1/2 cup for topping)
1 cup ( about 4 ounces) grated Parmigiano-Reggiano cheese (reserve 1/2 cup for topping)
1/2 cup (about 2 ounces) grated Fontina Cheese
1 pound dried medium elbow macaroni
3/4 pound fresh tomatoes (4 small), optional topping
1. Preheat oven to 375 degrees F. Butter a 3 quart casserole dish; set aside. Bring a large pot of water to boil, then add salt generously. Cook pasta 2 minutes less than manufacturer’s instructions (the outside should be cooked but the inside underdone). Transfer to a colander, rinse under cold running water, and drain well.
2. Make bread crumbs. Remove crusts and tear into large pieces. Pulse a few times in a food processor to form crumbs. Transfer to a medium bowl, add melted butter and toss. Set the breadcrumbs aside.
3. Warm the milk in a medium saucepan over medium heat. Melt the remaining 6 tablespoons butter in a high-sided skillet over medium heat. When the butter bubbles, add the flour. Cook, stirring, 1 minute.
3. While whisking, slowly pour in the warm milk a little at a time to keep mixture smooth. Continue cooking, whisking constantly, until the mixture bubbles and becomes thick, 8 to 12 minutes.
4. Remove the pan from the heat. Stir in salt, nutmeg, black pepper, cayenne pepper, 3 cups of cheddar cheese, 1 1/2 cups Gruyere cheese, 1/2 cup Fontina cheese, and 1/2 cup Parmigiano-Reggiano cheese until completely melted and sauce is smooth. Add pasta to sauce and stir to combine.
5. Pour the mixture into the prepared dish. Sprinkle the remaining 1 1/2 cups Cheddar cheese, 1/2 cup Gruyere cheese, and 1/2 cup Parmigiano-Reggiano cheese.
6. Slice the tomatoes and arrange on top, optional.
7. Sprinkle the prepared bread crumbs on top.
8. Bake for 30 to 35 minutes, or until the sauce is bubbly and the macaroni is browned on top. Transfer the dish to a wire rack for 5 to 10 minutes, serve.
