Preheat your oven to 425 F. Place baking paper on a roasting pan.
Chop cauliflower to smaller peaces, wash and dry with paper towel. Spread the cauliflower and garlic on a roasting pan. Sprinkle with olive oil, salt and pepper.
Place the roasting pan in the oven and roast for 30 minutes, until cauliflower is browned, stirring once after 20 minutes.
Transfer roasted cauliflower and garlic to a large saucepan, add vegetable stock and bring to boil. Add spices. Lower the heat and let it simmer for 15 minutes.
Stir in the coconut milk. Cook for another few minutes.
Puree the soup in blender or with an immersion blender until very smooth.