6 slices white sandwich bread, crusts removed
2 tablespoons unsalted butter, melted
8 ounces dried elbow macaroni
Sauce and Cheese Topping
3 tablespoons unsalted butter, plus more for baking dishes
1/4 cup finely diced yellow onion
1/4 cup all-purpose flour
3 cups whole milk
2 ounces Italian fontina cheese, grated (1/2 cup)
3 ounces Gruyere cheese, grated (1 cup), 1/3 cup reserved for topping
6 ounces extra-sharp white-cheddar cheese, grated (2 cups), 1/3 cup reserved for topping
2 ounces Parmigiano-Reggiano cheese, grated (1 cup), 1/2 cup reserved for topping
Coarse salt and freshly ground black pepper
1/8 teaspoon cayenne pepper
1/8 teaspoon freshly grated nutmeg
Slow-Roasted Tomato Slices (see recipe below)
Heat oven and boil pasta: Heat oven to 375 degrees. Bring a large pot of water to a boil, then add salt generously and cook pasta 2 to 3 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.
Meanwhile, make bread crumbs: Tear bread into large pieces and pulse a few times in a food processor to form very large crumbs. Transfer to a bowl, and add melted butter. Toss evenly to coat.
Prepare baking dishes: Butter eight 6-ounce shallow baking dishes or one 1 1/2-quart baking dish.
Make cheese sauce: Melt butter in a 4-quart pot over medium heat, add onion, and cook, stirring occasionally, until translucent, about 5 minutes. Whisk in flour and cook, stirring with a wooden spoon, until bubbling but not browning, about 45 seconds. Add milk and whisk to combine. Bring to a simmer, stirring with a wooden spoon (scrape across the bottom and around edge of pot to prevent scorching), until thickened, about 4 minutes. Add fontina, 2/3 cup grated Gruyere, 1 2/3 cups grated cheddar, and 1/2 cup Parmigianno-Reggiano, stirring until completely melted and sauce is smooth. Season with salt and pepper, add cayenne and nutmeg, and stir to combine.
Assemble and add cheese topping: Add pasta to sauce and stir to thoroughly combine. Pour into prepared baking dishes and sprinkle evenly with the reserved cheeses, followed by the bread crumbs. If using, top with roasted tomato slices and thyme.
Bake: Place dishes on a parchment-lined baking sheet and bake until bubbling and cheese is golden brown, 25 to 30 minutes. Let cool 5 minutes before serving.
Slow-Roasted tomato Slices
6 small tomatoes, sliced crosswise into 1/4-inch-thick rounds
2 tablespoons extra-virgin olive oil
Coarse salt and freshly ground pepper
1 teaspoon fresh thyme, leaves
Preheat oven to 400 degrees. Place tomato slices on rimmed baking sheets in a single layer. Drizzle with olive oil; season with salt and pepper and sprinkle with thyme leaves. Transfer to oven and roast until softened and browned in spots, about 20 minutes.
Recipe shared from: http://www.marthastewart.com/343982/macaroni-and-cheese?czone=food/comfort-foods-center/comfort-foods-dishes¢er=854190&gallery=274703&slide=260477