01 - Set the oven to 425°F (220°C).
02 - Toss carrots, onion, and garlic with 1 tablespoon olive oil, 1/2 teaspoon salt, and black pepper on a baking sheet. Roast for 25 to 30 minutes, turning halfway, until carrots are tender and caramelized.
03 - Heat remaining tablespoon of olive oil in a large pot over medium heat. Add ginger, cumin, and coriander; sauté for 1 to 2 minutes until fragrant.
04 - Add roasted vegetables to the pot. Pour in vegetable broth and bring to a boil. Reduce heat and simmer for 10 minutes.
05 - Stir in coconut milk, reserving 2 tablespoons for garnish if desired. Simmer for an additional 5 minutes.
06 - Remove from heat and purée the soup using an immersion blender or in batches with a standard blender until smooth.
07 - Stir in lime juice and adjust salt to taste.
08 - Ladle soup into bowls, swirl reserved coconut milk on top, and garnish with fresh herbs if desired.