In a large stock pot, combine the broccoli (if using fresh), cauliflower, celery, carrot, onion, water, and bouillon granules. Bring to a boil. Reduce heat; cover and simmer for 13 minutes or until vegetables are tender (do not drain).
In a large saucepan, melt butter. Stir in the flour, garlic powder, salt, and pepper until smooth. Gradually add milk. Bring to a boil over medium heat; cook and stir for 2 minutes or until thickened. Reduce heat. Stir in the cheese until melted. Add hot pepper sauce if desired. Stir into the cauliflower mixture.
Notes
*I used a bag of steamable broccoli because I always have one on hand. If you choose to do so, add it to the veggie mixture at the end of step 1.
Recipe by Simple, Sweet & Savory at https://www.simplesweetsavory.com/chunky-cheesy-broccoli-cauliflower-soup/