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