1. Heat oil over medium heat in a 6-quart stockpot. Add onions and saute until they begin to soften, about 5 minutes. Add garlic and saute for 2 minutes more. Add squash, broth, curry powder, and salt and bring to a boil. Reduce heat and simmer uncovered until squash is tender, 12 to 15 minutes.
2. Remove from heat, stir in honey, and puree with a mixer or in batches in a blender until smooth
3. Ladle into serving bowls and drizzle yogurt over each.