So simple it's silly but when they're in season and sweet and abundant and cheap don't forget about carrots! Best roasted with salt and olive oil at a high temp (I do it a 400) until you can slide a knife through effortlessly. Then sautée some spring onion or leek or sweet yellow onion and toss it in a blender with veggie or chicken broth. I like to throw in a dollop of sour cream but you can add milk or yogurt or soymilk. Sprinkle fresh dill on top or back up to the onion sautée and add a bit of fresh ginger to give it zip. Too easy to write a whole recipe for it. And really, if you roast them and blend them you've got the soup basics. The rest is up to you and your palate.
Make a little extra and take it to a friend. No better bonding than soup!