How to Make It
Preheat the oven to 400°. In a small skillet, toast the coriander seeds and peppercorns over moderately high heat until fragrant, about 30 seconds. Transfer to a spice grinder and let cool completely. Grind the spices to a powder and transfer to a small bowl. Stir in the olive oil, garlic, turmeric and crushed red pepper.
On a large rimmed baking sheet, drizzle the cauliflower with the olive oil mixture and toss to coat. Season with salt and roast for 25 minutes, until the cauliflower is tender; scrape the cauliflower into a serving bowl. Add the shallot rings, kumquats and cilantro and toss well. Serve hot or warm.