Ingredients Kosher salt Vegetable oil 1 pound elbow macaroni or cavatappi 1 quart milk 8 tablespoons (1 stick) unsalted butter, divided 1/2 cup all-purpose flour 12 ounces Gruyere, grated (4 cups) 8 ounces extra-sharp Cheddar, grated (2 cups) 1/2 teaspoon freshly ground pepper 1/2 teaspoon ground