Bring a large pot of salted water to a boil and add macaroni. Cook for 8 minutes, or until al dente. Drain and set aside.
In a large saucepan, melt butter over medium heat. Add flour and whisk until smooth. Gradually add milk and continue whisking until thickened and bubbly.
Stir in cheddar cheese, mustard, salt, and pepper. Add macaroni to the cheese sauce and stir to combine.
Transfer the macaroni and cheese to a greased 9x13-inch baking dish. Sprinkle bread crumbs over the top and bake for 20 minutes, or until golden and bubbly.
Let cool for 5 minutes before serving.
Interesting Facts
Mustard Macaroni and Cheese has been a popular dish since the 1800s.
Mustard adds a tangy flavor to the dish, making it a unique twist on the classic version.
It's a great side dish to serve with grilled meats or roasted vegetables.
This dish is a great way to use up leftover cheese.