This low-calorie Cream of Mushroom Soup with Green Onions is quick to make. Each serving is only 60 calories. The dark brown caps of cremini mushrooms add a delightful earthiness to the pureed soup.

If you cook often, you have had this experience: the dish that keeps reinventing itself. I’ve made this green soup with yams instead of potatoes. I made it with all spinach and nutmeg. A friend ...