Preheat oven to 425 F.
In a large ½ pan baking tray, combine butternut squash, cauliflower, onion, garlic, sage and olive oil. Add salt and pepper to taste, and toss to combine. Bake for 20-25 minutes, until vegetables are soft and tender.
Transfer vegetables into a food processor or a blender (in 2 batches if needed). Add 2 cups of stock and puree until smooth.
Transfer soup to a large pot, add remaining stock, and stir to combine. Bring soup to a simmer, and stir in coconut milk. Season with more salt and pepper, to taste. If the soup is too thick, add some water until desired consistency is reached.
Serve with a drizzle of coconut milk and fresh herbs or toasted pepitas on top.
