Preheat the oven to 425 degrees F. Place the carrots on a baking sheet and toss with the olive oil. Sprinkle all over with salt and pepper. Roast for 20 to 25 minutes, until golden and caramelized.
While the carrots are roasting, heat the coconut oil in a stock pot. Once it melts, stir in the onions, garlic and ginger with a big pinch of salt and pepper. Cook, stirring often, until the onions soften, about 5 to 6 minutes. Turn the heat to low if the carrots are not done yet.
Once the carrots are done roasting, add them to the pot. Add in the stock and bring the mixture to a boil. Reduce to a simmer and cook for 10 minutes. Turn off the heat and very carefully transfer the mixture to a blender. Cover the blender with a towel and blue until pureed. Pour the soup back into the pot and heat it over low heat.
Stir in the coconut milk and the lime juice. Stir until the soup is warmed throughout. Taste and season with more salt and pepper as needed.
Serve with a drizzle of coconut milk or cream, plus scallions on top.