Preheat oven to 450°F.  Line sheet pan with parchment. 2. Coat 1/3 of the cauliflower in za'atar, 1/3 in shawarma, and 1/3 in harissa.  On a prepared sheet pan spread out coated cauliflower.  Drizzle with olive oil and sprinkle with salt.  Roast for 20 minutes or until browned.  3. Remove from the oven and finish prepared tahini, garnish with fresh torn parsley or cilantro. Serve warm.