2 cups whole wheat elbow macaroni
1 1/2 cups milk
2 tablespoons unsalted butter
2 tablespoons all-purpose flour
4 ounces Gruyere cheese, grated
3 ounces extra-sharp Cheddar, grated
2 ounces blue cheese, crumbled
1/4 teaspoon freshly ground black pepper
2 slices sandwich bread, crusts removed
2 tablespoons freshly chopped basil leaves
Preheat the oven to 400 degrees F.
Drizzle oil into a large pot of boiling salted water. Add the macaroni and cook according to the directions on the package, 6 to 8 minutes. Drain well.
Meanwhile, heat the milk in a small saucepan, but don’t boil it. Melt the butter in a medium pot and add the flour. Cook over low heat for 2 minutes, stirring with a whisk. While whisking, add the hot milk and cook for a minute or 2 more, until thickened and smooth. Off the heat, add the Gruyere, Cheddar, blue cheese, 1 teaspoon salt, pepper, and nutmeg. Add the cooked macaroni and stir well. Pour into a baking dish.
Place the bread slices in a food processor fitted with a steel blade and pulse until you have coarse crumbs. Add the basil and pulse to combine. Sprinkle the bread crumb mixture over the top of the pasta. Bake for 35 to 40 minutes, or until the sauce is bubbly and the macaroni is browned on the top.