1. In a large stockpot over medium-high heat, saute onion and garlic in oil and sherry for 10 minutes. Add carrots and cook 5 minutes. Add stock and bring to a boil.
2. Lower heat to medium and cook soup for 20 minutes. Puree in batches in a blender and return to pot. Add cardamom, yogurt, nutmeg, and orange rind. Heat through and serve.
