Easy cheesy vegetable casserole

Bring water to a boil in a large pot over high heat. Add the potatoes and cook, covered, for 5 minutes. Add the cauliflower, broccoli, carrots, onion, and frozen green beans. Return water to a boil, cover, and cook 10 to 12 minutes until vegetables are tender. Drain. Spray a 2-quart baking dish with cooking spray. Add cooked vegetables. Combine the canned soup and milk. Pour soup mixture over the vegetables, mixing gently. Preheat oven to 350°F. Cover and bake casserole for 20 to 25 minutes. Uncover and sprinkle with cheese. Bake 3 to 4 minutes longer, until cheese melts.