You could also make this soup with red peppers. Better yet, make both and serve a ladle of each in the same bowl. When you buy peppers for roasting, choose those with flat sides as the very curvy ones don't roast evenly. Roasting over a flame results in roasted peppers with a firmer texture, perfect for salads etc. Oven roasting result in a softer pepper; using the food mill to puree eliminates the need to spend time peeling and seeding. To make this meal even faster, you can roast and puree the peppers a day or two before. Roasted pepper puree also freezes beautifully.