Preheat the oven to 400°F. Spread the cauliflower florets onto a half sheet pan. Drizzle with 2 tablespoons of olive oil and add salt and pepper to taste. Roast the cauliflower at 400°F for 15 minutes, turning once. Remove from the oven when done.
In a large stockpot, heat 1 tablespoon olive oil over medium heat. Sauté the shallots, garlic, and thyme just until fragrant. Add the roasted cauliflower and broth to the stockpot. Cover and simmer until the cauliflower is tender (about 20-30 minutes). Stir in the half and half.
Using an immersion blender (hand blender), puree the soup in the pot until smooth. If the soup is too thick, thin with hot broth, as needed. Garnish with leftover herbs, extra cauliflower, and extra olive oil. Serve warm.
Notes
TIPS:
Break the cauliflower into the same sized pieces for even cooking.
Swap in a sweet onion if you cannot find shallots.
Go dairy-free or omit the half and half for a vegan recipe. The soup will still be creamy thanks to the cauliflower and oil.