Grammie's Broccoli Cheese Soup

1 large bunch of Broccoli
5 T flour
3/4 tsp salt
3/4 cup chopped onion
2 cups chicken broth
1 cup butter
2 cups half and half
2 cups (1/2 block) Velveeta cheese
1/2 tsp Worcestershire

Cook vegetables and save 1 cup broth.  Melt butter and cook onions until clear. Blend in flour and broths.  Boil and stir.  Add remaining ingredients.