1. Adjust oven rack to middle position and heat oven to 450 degrees. Toss squash, shallots, oil, 1 teaspoon salt, and ½ teaspoon pepper in large bowl, then arrange in single layer in large roasting pan. Roast, stirring occasionally, until vegetables are golden brown and softened, about 45 minutes. Add ½ cup broth to pan and scrape up any browned bits with wooden spoon. Return to oven and cook until liquid has reduced and vegetables are glazed, about 5 minutes.

2. Working in 2 batches, puree squash mixture and remaining broth in blender until smooth. Transfer pureed squash mixture to large saucepan and stir in honey, lime juice, cumin, and cream. Bring soup to simmer over medium-low heat, adding ¼ cup water at a time as necessary to adjust consistency. Just prior to serving, stir in cilantro and chiles. Serve with dollop of sour cream, if desired. (Soup can be refrigerated in airtight container for 3 days.)