In large saucepan add all vegetables. Cover with water, bring to boil and boil 5-7 minutes. Drain but reserve 2 C water from boiling. Set aside.
In soup pot or large dutch oven, melt butter; add flour and stir. Pour in all milk and stir over medium heat for a couple minutes until thickened. Add cheese and salt and pepper. Add vegetables and 1-2 C liquid from boiled veggies.
Give it a stir and simmer for 15 so flavors will combine.
You may add more milk, water or chicken broth if deired.
Recipe by The Gingham Apron at https://www.theginghamapron.com/cauliflower-cheese-soup/