In a pinch, this is a quick microwave dinner that you can sink your teeth into.
In a medium saucepan, boil water. Add macaroni and cook 8 minutes; drain.
In a glass or microwave safe dish, melt butter for 30 seconds. Blend in flour and salt.
Stir in milk until smooth.
Microwave 2 minutes, stirring with a fork after 1 minute, until thickened.
Stir in cheese until completely melted.
Pour well drained macaroni into cheese sauce, mixing well.
Microwave at medium-high heat for 3 minutes.
If desired, sprinkle top with bread crumbs before serving.