In a large saucepan heat oil over medium heat. Add onion and saute until softened, 6 to 8 minutes. Add garlic and cook, stirring for 1 minute more.
Add cauliflower, cashew milk, salt, and pepper. Cover, bring to a boil, then reduce heat to simmer until cauliflower is very tender, about 10 minutes.
Transfer mixture to a blender, add miso, and puree. Use immediately or let cool and refrigerate. To use, reheat gently over medium low heat, stirring frequently, until hot.
This nutritional information refers to each serving of the entire recipe and not just the products used as ingredients.