Heat the oven: Set to 450°F (230°C). Place a large sheet pan inside to preheat for extra browning.
Prep the cauliflower: Remove leaves and core.
Cut into large florets, then slice big pieces into 1/2-inch slabs for more flat, caramelized surfaces.
Season: In a large bowl, toss cauliflower with olive oil, salt, pepper, smoked paprika, cumin, garlic powder, and red pepper flakes. Add lemon zest.
Roast hot and undisturbed: Carefully pull out the hot pan, spread cauliflower in a single layer with space between pieces. Roast 15 minutes.
Flip for color: Stir or flip pieces, then roast 10–12 more minutes until deeply golden with crisp edges and tender centers.
Finish bright: While hot, squeeze fresh lemon juice over the cauliflower.
Taste and adjust salt or lemon as needed.
Serve: Top with chopped herbs. Plate over grains, tuck into pitas with tahini or yogurt sauce, or serve alongside a green salad.