Cheesy Broccoli Chowder

3 c chicken broth
2 c diced potatoes
2 c diced carrots
2 c frozen broccoli
1 chopped green onion or 1 c chopped celery
1/4 tsp pepper
1/4 c margarine
1/3 c flour
2 c milk
2 c grated cheddar
1 can cream chicken soup

In a large saucepan, bring chicken broth to a boil. Reduce heat and add potatoes, carrots, broccoli, onion (or celery), and pepper. Cover and simmer until vegetables are tender. Melt butter in another pan, add flour, and mix well. Gradually stir in milk, and cook until thickened over low heat. Stir in cheese and cook until melted. Add to broth along with cream of chicken soup.