Preheat oven to 450F.
Place asparagus, onion & smashed garlic in a large glass baking dish or cookie sheet. Drizzle with oil and season with salt and pepper. Roast for 12 minutes, or until asparagus is soft, stirring once. Remove from oven and transfer asparagus, onions and garlic to a blender. Add broth and coconut milk, adding more coconut milk if you like it creamier. Blend until smooth. (You might have to do this part in batches depending on the size of your blender). If you have a Vitamix, blend on HIGH for 3-4 minutes until hot or transfer soup to a large pot to finish heating. Add salt and pepper to taste. Garnish with parsley.