It's not really a "summer" soup, but it sounded so good I had to try it. I love Isa Moskowitz's special secret butternut squash tip...I'll let you read the book (Vegan with a Vengeance). I have some special squash tips myself - I've always just cut up the squash and roasted, boiled or steamed squash with the skin on. I just scoop the cooked squash out of the skin, wearing rubber gloves if it's hot, before I eat the squash. Some people I know eat squash, skin and all. And, the seeds are good roasted and salted too. If the squash is difficult to cut in half, I poke a couple holes in it, pop it in the micro for a couple minutes until soft, and cut it in half (watch for hot spots).
Anyway, the soup turned out wonderful, even without the spicy chile. The roasted butternut squash is added to a puree of fresh ginger, garlic, and onions (one of my favorite kinds of soup). My toddler has added "soup" to his list of first words after this soup!