Roasting at high heat is one of the best ways to cook cauliflower. Dry heat caramelizes the vegetable's juices, and none of its flavor is lost to cooking water. Although cauliflower is delicious tossed with just olive oil, salt, and pepper, the combination of subcontinent spices really makes this dish extra special. Feel free to experiment with your own versions.
Position a rack in the middle of the oven and preheat to 450 degrees F.
Place the cauliflower in a large bowl and drizzle with the canola oil, tossing to completely coat the florets. Use more oil if needed.
Combine the curry powder, cumin, garlic salt, cardamom, ginger, cayenne, and Chinese Five Spice Powder in a small bowl and whisk to blend. Sprinkle half of the spice mixture over the cauliflower and toss to coat the florets. Repeat with the remaining spice mixture, taking care to ensure the florets are evenly coated with the spices.
Transfer the cauliflower to a rimmed baking sheet and spread the florets in an even layer. Roast, stirring once or twice, until the cauliflower is crisp-tender and browned, 15 to 20 minutes. Serve hot.