Steam broccoli, covered, 3 minutes or until crisp-tender.
Melt the butter in a saucepan over medium heat.
Add flour, and cook for 1 minute, stirring constantly. Gradually add milk, stirring with a whisk until blended. Cook 15 minutes or until thick, stirring constantly. Stir in cheeses, salt, and pepper, and cook 5 minutes or until cheese melts. Stir in broccoli and pasta.