Melt butter in medium size pot over medium heat, add onions and celery, sautee for 3 minutes, add garlic, sautee 2 minutes, add flour, mix till well combined, slowly add milk and chicken broth, bring to a boil, simmer till thickened, about 5 minutes, add broccoli, bring to boil, turn heat off and add cheese, stir till melted, add seasoning to suit your taste, enjoy!