2 1/4pounds cauliflower, two-thirds roughly chopped (including the core); one-third cut into small florets
1/2teaspoon chopped thyme leaves
1quart good vegetable stock
1pint skim milk
1teaspoon ground cumin
2handfuls of arugula leaves
1/2teaspoon ground white pepper
Preheat the oven to 425F.
Heat half the vegetable oil in a large saucepan. Add the onion, garlic, celery, and carrot and cook for 8–10 minutes over medium to low heat to lightly color and soften the onion. Add the potato, and cook until the potato starts to stick, and the edges start to soften.
Add the roughly chopped cauliflower, bay leaf, thyme, and stock to the pan. Bring to a boil, then reduce the heat and simmer for 15–20 minutes. Add the milk, and warm through without letting the soup boil.
Meanwhile, toss the cauliflower florets with the remaining oil in a bowl, then add the cumin and toss again. Place on a baking sheet and roast for 12–15 minutes, until the cauliflower begins to brown, but still retains some bite.
Process the soup in a blender with the arugula and white pepper. Blend it in batches, then pass through a fine sieve. Check the seasoning.
Drain the roast cauliflower and divide between the hot soup bowls. Pour in the soup and serve immediately.