Cook asparagus spears in boiling, salted water 10 to 20 minutes, or until just tender.
In a saucepan, melt ¼ c. butter and stir in flour and salt; blend in enough milk to make a smooth paste. Stir in remainder of milk and cook over medium heat until sauce is thick, stirring constantly. While sauce is hot, stir in shredded cheese and red pepper. Stir until cheese