1. Heat chicken broth and broccoli in saucepan over medium high heat until boiling. Bring heat down to medium and cook another 7-8 minutes (until broccoli is tender but not mushy).
2. Combine flour and milk in a little bowl. Slowly stir into soup. Keep cooking until soup is boiling again, stirring occasionally. Fully boil for one minute.
3. Bring heat down to low and add cheese. Cook and stir until cheese is melted, about 5 minutes.