Preheat the oven to 180°C and line a large tray with baking paper.
Break the cauliflower into florets and toss with the cumin, nutmeg and 2 tablespoons of olive oil. Place the cauliflower onto the baking tray in a single layer and bake for about 15 minutes or until the cauliflower is tender.
While the cauliflower is roasting, make the chimichurri by combining 2 tablespoons of olive oil with the Chimichurri Spice and lemon juice. Set aside.
Prepare the base of the soup by heating another tablespoon of olive oil in a large pan over medium heat and cook the onion, celery and garlic for about 5 minutes or until softened, but not browned. Add the roasted cauliflower, bay leaves, water and vegetable stock. Bring to a boil and simmer for 15 minutes. Once it is done, remove the bay leaves. With a blender, puree the soup in batches.
Return it to the pan and over low heat, stir in the cream.
Serve the soup with a generous swirl of chimichurri sauce and an extra drizzle of cream. Season to taste.