1. Warm oil in a pot over medium heat. Add onion; sauté until softened, 6 to 8 minutes. Add ginger and garlic; sauté until fragrant, about 1 minute.
2. Raise heat to medium-high; stir in carrots. Pour broth into pot, cover and bring to a simmer. Remove cover, reduce heat to medium to maintain a simmer and cook until carrots are very tender, about 25 minutes. Remove soup from heat and let cool slightly.
3. Working in batches, purée soup in a blender until smooth. Transfer to a large bowl, cover and refrigerate until chilled, at least 2 hours.
4. Just before serving, stir in lime juice and yogurt. Season with salt and pepper. Serve chilled, garnished with lime wedges, if desired.
MyRecipes is working with Let's Move!, the Partnership for a Healthier America, and USDA's MyPlate to give anyone looking for healthier options access to a trove of recipes that will help them create healthy, tasty plates. For more information about creating a healthy plate, visit www.choosemyplate.gov.