Cook the elbow macaroni according to package instructions.
While pasta is cooking (because I hate letting cooked pasta sit and get all weird and crusty!), melt the butter in a medium saucepan over medium heat.
Whisk in flour, salt, and pepper, stirring constantly for 1 minute.
Reduce burner temperature to medium-low and slowly add the milk to flour mixture, whisking constantly for a couple minutes until the mixture is just barely thickened.
Remove mixture from heat and stir in cup shredded cheese, stirring just until melted.
Add the cooked macaroni noodles, tossing to coat thoroughly.
Serve!