In small saucepan, melt butter. Add flour stirring with a whisk. Cook 1 minutes stirring constantly.
Add broth to butter/flour mixture, stirring with a whisk. Continue cooking and stirring until thickened and bubbly. Add salt and pepper to taste.
In lightly greased casserole dish, place croutons on bottom. Cover with 1/3 of sauce. Add brocolli and cover with 1/3 sauce. Add chicken and cover with remaining sauce. Sprinkle parmesan cheese over top Bake at 375* for 35 mins or until heated through and bubbly.