Cheddar Broccoli Soup

1 (16 oz.) pkg frozen broccoli - or fresh
6 carrots, sliced
4 stalks celery, sliced
1 medium onion, chopped
3 cubes butter or margarine
1 1/2 cups flour
10 cups water
10-12 chicken bouillon cubes (to taste)
1 (16 oz.) container Cheez Whiz or Velveeta cheese

Steam vegetables until almost tender. In a separate bowl, microwave butter until melted. Stir in flour and mix until smooth. In a large saucepan, dissolve bouillon cubes in boiling water. Add a cup of bouillon water to the butter/flour mixture and whisk together. Then add to boiling water and stir. Add drained vegetables to soup. Add Cheez Whiz or Velveeta cheese. Stir until melted.