- 3 tablespoons unsalted butter, plus more for greasing pan
- Salt
- 1 pound elbow or shell pasta
- 3 tablespoons all-purpose flour
- 1 1/2 cups milk
- 1/2 teaspoon yellow or Dijon mustard
- 1/4 teaspoon freshly ground black pepper
- 2 cups shredded extra-sharp cheddar cheese
- 1/2 cup grated Parmesan cheese
- 2 large eggs
- Pinch each of salt and freshly ground black pepper
- 1 cup all-purpose flour
- 1 cup seasoned bread crumbs
- 1/4 cup grated hard cheese, such as Parmesan or Pecorino Romano
- Nonstick cooking spray
- Belgian or standard waffle iron
- Preheat the oven to 375°F. Butter a 9×5-inch loaf pan and set it aside.
- Bring a large pot of salted water to a boil over high heat. When the water is at a rolling boil, add the pasta. Cook the pasta until it is slightly underdone, checking a few minutes before the cooking time on the package directions. (If you bite into a piece, you should be able to see a very thin core of uncooked pasta.) Drain the pasta and set aside.
- Melt the 3 tablespoons butter in a large saucepan over medium-low heat. Add the flour to the melted butter, whisking constantly. Continue to whisk for 2 minutes. Add the milk, 1/2 cup at a time, waiting until the mixture is thoroughly combined before adding more. Whisk constantly over medium-low heat until the mixture thickens to the consistency of heavy cream, about 5 minutes.
- Turn off the heat, add the mustard, 1 1/4 teaspoon salt, and pepper, and stir. Add the shredded cheddar cheese a handful at a time, stirring constantly until the cheese melts. Add the pasta to the cheese mixture, stir to coat thoroughly, and then pour the cheese-covered pasta into the prepared loaf pan.
- Sprinkle the grated Parmesan cheese on top and bake until the top is brown and crispy, about 20 minutes.
- Set aside to cool for an hour, then cover with plastic wrap and refrigerate until the macaroni is well chilled and the cheese has solidified (at least 2 hours, or overnight).
- Cut the macaroni and cheese into slices about 1/2-inch thick.
- Preheat the waffle iron on medium. Preheat the oven on its lowest setting.
- In a small bowl, beat the egg with a pinch each of salt and pepper.
- Set out 3 shallow bowls. Measure the flour into the first. In the second bowl, place the beaten eggs. Mix the bread crumbs with the cheese in the third.
- Take a slice of the macaroni and cheese, and, handling it gently, coat both sides in the flour. Then dunk both sides in the egg. Finally, coat both sides with the bread crumbs, pressing the mixture so it sticks. Set aside the slice and repeat with the remaining slices.
- Coat both sides of the waffle iron grid with nonstick spray. Place the macaroni and cheese slices in the waffle iron, close the lid, and cook until heated through and golden brown, 3 minutes.
- The extraction process can be tricky. With a silicone spatula, loosen the edges of the macaroni and cheese. Use the spatula to gently pry the macaroni and cheese from the waffle iron and then support the bottom with the spatula while you lift it out with tongs.
- Repeat Steps 5 through 7 until all of the macaroni and cheese has been waffled. Keep the finished macaroni and cheese warm in the oven.