Ingredients1/2 pound dried elbow macaroniCoarse salt and freshly ground pepper3 tablespoons unsalted butter1/4 cup all-purpose flour3 cups whole milk1/2 cup finely grated Italian fontina cheese2/3 cup finely grated Gruyere cheese1 2/3 cups finely grated extra-sharp white Cheddar cheese1/2 cup finely grated Parmigiano-Reggiano cheese1/8 teaspoon cayenne pepper1/8 teaspoon freshly ground nutmegPinch of white pepperDirectionsBring a large pot of water to a boil, then add pasta; salt generously and cook pasta to manufacturer’s instructions. Transfer to a colander, rinse under cold running water, and drain well. Melt butter in a 4-quart pot over medium heat. 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 and smooth. Reduce heat to a simmer and cook for 20 minutes. Add fontina, Gruyere, Cheddar, and Parmigiano-Reggiano cheeses, stirring until completely melted and sauce is smooth. Season with salt and black pepper, add cayenne and nutmeg, and stir to combine. Add pasta to sauce along with white pepper and salt; stir to thoroughly combine. Serve immediately.Tips/TechniquesThis macaroni and cheese recipe appears in the "Sauces" episode of "Martha Stewart's Cooking School." Visit the episode guide to watch a preview and get a cooking tip.