Cook macaroni shells according to the directions on the package. Drain; set aside.
Melt butter in 3-quart saucepan until sizzling; stir in flour and mustard. Add broth and half & half. Cook on medium-heat, stirring constantly for 4-5 minutes or until it comes to a boil.
Reduce heat to low; stir in cheese until melted. Stir in cooked macaroni and ham. Cook 4-5 minutes or until heated through.