Prep Work: Shred cheese if needed. Boil noodles.
Boil noodles according to package directions.
Melt butter in skillet. When bubbling, whisk in flour. Pour in some milk and whisk until smooth. Keep adding milk with whisk until all combined. (see Broccoli Chicken video for whisking gravy technique.)
Add cheese and keep stirring until melted and slightly thickened; up to 10 min.
Drain noodles and return to pot and stir in cheese sauce. Add 1/2 tsp. pepper and salt, then keep adding salt 1/4 tsp. at a time to bring out the taste.