1/4 c. fat
1/4 c. flour
1/2 tsp. salt
2 c. milk
1/2 tsp. mustard
1 1/2 c. cut up cheese
3 c. cooked macaroni

Melt fat, mix in flour and salt, add milk slowly, stirring until sauce thickens. Add mustard and cheese, low heat until cheese melts, add macaroni.