Bring a large pot of water to boil.
Add a sprinkling of salt, then boil the noodles according to package directions.
Once al dente, drain the pasta and return it to the pot.
Add the butter and stir until butter has melted.
In a separate small bowl, whisk together the eggs, evaporated milk, cayenne, 1 tsp. salt, pepper, and mustard.
Stir the milk mixture into the noodles until incorporated.
Add in the cheese and stir over low heat until cheese has melted, approximately 3 minutes.
Serve immediately.
