Broccoli Cheddar Cheese Soup

2 tbsp butter or margarine
3 tbsp flour
4 cups low-fat milk
3/4 tsp salt
1/2 tsp dry mustard
1/4 tsp cayenne pepper
10 oz fresh or frozen chopped broccoli, thawed & drained
1/2 cup finely chopped red bell pepper
6 oz Cheddar cheese, shredded
2 tbsp chopped chives or green onion tops

Melt butter in large saucepan over medium heat
Add flour; cook & stir 30 seconds or until bubbly
Add milk, salt, dry mustard and cayenne pepper
Bring to a boil over high heat, stirring frequently
Add broccoli and red bell pepper, return to a boil
Reduce heat to low
Simmer, uncovered, for 5 minutes, stirring occasionally
Add cheese, stir over low heat until cheese melted (do not boil)
Ladle into soup bowls; top with chives