12 cups cauliflower florets (from about 4 pounds cauliflower)
1 large onion, peeled, quartered
1 teaspoon coriander seeds
1 teaspoon cumin seeds
3/4 cup olive oil
1/2 cup red wine vinegar
3 1/2 teaspoons curry powder
1 tablespoon Hungarian hot paprika
1 3/4 teaspoons salt
1/4 cup chopped fresh cilantro
Preheat oven to 450°F. Place cauliflower florets in large roasting pan. Pull apart onion quarters into separate layers; add to cauliflower. Stir coriander seeds and cumin seeds in small skillet over medium heat until slightly darkened, about 5 minutes. Crush coarsely in mortar with pestle. Place seeds in medium bowl. Whisk in oil, vinegar, curry powder, paprika, and salt. Pour dressing over vegetables; toss to coat. Spread vegetables in single layer. Sprinkle with pepper.
Roast vegetables until tender, stirring occasionally, about 35 minutes. (Can be made 2 hours ahead. Let stand at room temperature. Rewarm in 450°F oven 10 minutes, if desired.)
Mound vegetables in large bowl. Sprinkle with fresh cilantro. Serve warm or at room temperature.