Bring 3 cups of water to a rolling boil, add pasta, and cook until al dente.

Shred 1/2 cup extra sharp, white American cheese.

In a separate pan, heat milk and butter. When combined, add flour and stir until mixture thickens. Add cheese and mustard, and stir vigorously for 2 minutes.

Plate noodles, pour cheese sauce over noodles, and sprinkle with ground black pepper.