Start by washing the cauliflower and cutting it into evenly sized florets. I always pat them completely dry with a towel because moisture prevents crisping. Uniform pieces ensure everything cooks at the same rate.
Place the florets in a large bowl and drizzle with olive oil. Sprinkle in salt, garlic powder, and black pepper, then toss thoroughly to coat every piece. Make sure each floret has a light layer of oil to encourage browning.
Spread the cauliflower in a single layer on a baking sheet. Roast in a preheated oven at 425°F (220°C) for 25–30 minutes, flipping halfway through. The goal is crispy, caramelized edges and fork-tender centers.
While the cauliflower roasts, combine tahini, lemon juice, garlic, herbs, salt, and water in a food processor. Blend until smooth and creamy. If it seems too thick, add water one tablespoon at a time until silky.
Transfer the roasted cauliflower to a serving platter. Serve the tahini sauce on the side or drizzle it directly over the top. Garnish with extra herbs for a vibrant finish.