Spread cauliflower, onion slices and garlic cloves on a baking sheet. Drizzle melted coconut oil over the top and place in the oven. Roast for 30 to 40 minutes or until cauliflower is fork tender.
Once done, transfer veggies and broth to a large pot over medium heat. Add in all other ingredients except coconut milk. Right before mixture begins to boil, turn heat down to low and simmer for 20 minutes.
In a blender, in shifts, puree the broth and veggie mixture until smooth. Once everything is pureed, transfer back into pot.
Stir in coconut milk, simmer for another 10 minutes, and serve.