Hi Granny, here's a link to a winter soup I did a recipe for. It has pureed carrots but you could easily use broccoli and cauliflower (some pureed and a few finely cut) instead. The recipe has bacon in it which you don't eat now but you can use the veggie bacon that you can buy at the grocers for that smoky flavor...mmmm.
Also, I used cheddar. Too much heat can make a grainy or stringy soup so a lower heat and nice stirring will help. Any creamy or soft cheese melts really well and is less difficult to work with and of course, it has to be a "good" cheese, nothing expensive but check the ingredients, too much oil in a lesser cheese will grain and string your soup......hope that helps some!
Northwestern Winter Cheese Soup