Heat oven to 450 degrees, and roast cauliflower florets until golden, about 20 minutes.
In a large pot, or dutch oven, heat oil, then add potatoes and onion and sweat until translucent.
Add the garlic, cumin and curry powder, and stir. Then add stock.
Add the roasted cauliflower, and then stir until softened.
Puree in batches in a blender, or use immersion blender, and season taste. Serve alone or garnish with items such as leftover cauliflower, chopped chives or basil.