Snap ends off asparagus. Shave 3 spears with a vegetable peeler to create ribbons, set aside. Chop remaining asparagus.
In a large pot over medium heat, sauté onion in oil until translucent. Add chopped asparagus and cauliflower and cook for about 3 more minutes.
Add stock and bring to a boil, reduce heat and simmer 20-30 minutes until cauliflower is very tender.
Puree until smooth. Season with salt and pepper, and serve garnished with shaved raw asparagus and fresh pepper.