1. Preheat oven to 425 degrees F.
2. In a 9-by-13-inch pan, mix poblano and cubanelle peppers, onions, salt, pepper, and oil. Place pan on middle rack and roast, stirring once or twice, for 30 minutes. Vegetables will turn a light golden brown around edges and will be tender when pierced with the point of a sharp knife.
3. Meanwhile, in a blender or food processor, blend chipotle peppers with yogurt until smooth. Pour chipotle cream into a bowl and reserve. You don't need to clean out the blender as a touch of this spicy chipotle cream will be good in the soup.
4. Remove roasting pan from oven and let cool slightly.
5. Working in batches, puree vegetables with broth until smooth in the blender or food processor you used to puree the chipotle cream. Transfer puree to a large pot. Reserve about 1/2 cup broth, pour in pan, and scrape up any bits from bottom of pan, then add to soup pot.
6. Heat pureed soup over medium-low heat until barely simmering. Serve hot, each bowl topped with a dollop of chipotle cream and sprinkling of tortilla chips.
Source: Hannaford fresh Magazine, January - February 2008