Heat the coconut oil in a large pot over medium heat.
Add the chopped onion and garlic and cook until softened, about 5 minutes.
Add the curry powder, ginger, and turmeric and cook for 1 minute more, stirring constantly.
Add the sweet potato and vegetable broth to the pot. Bring to a boil, then reduce heat and simmer for 20-25 minutes, or until the sweet potato is tender.
Stir in the coconut milk and heat through. Season with salt and pepper to taste.