Clean, peel and chop all vegetables into bite sized pieces. Brown the onion slightly in a large pot, add the carrot and sweet potato along with the 2 cans coconut milk, and ginger. Simmer 20 minutes until potato is soft. Either use an immersion blender to puree, or carefully ladle batches into a blender and put back into the pot.
Add the chopped cauliflower, nut butter, and enough water to cover. Simmer for 10 minutes. Add 2 Tablespoons sriracha, or to taste.