Renae's Chicken Broccoli Soup

4 c. water
3 tsp. chicken bouillon cubes
2 bunches of fresh broccoli
4 chicken breasts, cut up.
Boil 20 minutes with the lid on, then add one cube of butter and stir until it melts. Add 2 cans of evaporated milk, 1 T. dry mustard and one cup cheddar cheese. If you need to make it thicker, make a paste of 1/4 c. flour and water.