Preheat oven to 400.
Toss cauliflower and asparagus with 1 T olive oil. Place cauliflower on baking sheet and roast 20 minutes.
After 20 minutes, add asparagus and flip the cauliflower. Roast another 15-20 minutes until soft and caramelized. Set aside.
Heat remaining T olive oil in a soup pot or dutch oven over medium high heat. Add shallots. Cook, stirring, until shallots are soft. Add roasted vegetables, salt, pepper, crushed red pepper and broth. Bring just to a boil, then reduce heat and simmer for 5 minutes.
After 5 minutes, remove from heat and carefully, using an immersion blender, process the soup to desired consistency.
Check for seasoning and adjust as needed.