1. Preheat oven to 400 degrees Fahrenheit. Line a large baking tray with Gefen Parchment Paper. Set a large pot of well-salted water to boil for the penne.
2. On the baking tray, toss the cauliflower florets and chickpeas with two tablespoons of the oil, za’atar, and salt and pepper to taste, spreading everything out in a single layer. Roast for 25–30 minutes, or until the cauliflower florets are easily pierced with a fork and golden in places.
3. Reserve some cilantro leaves for garnish, if desired. Combine the torn cilantro, tahini, lemon juice, garlic, sriracha, remaining oil, and water in a blender. Blend into a smooth sauce.
4. In the meantime, cook the penne al dente in the prepared pot. Drain the penne and return it to the same pot.
5. Add the roasted cauliflower and chickpeas and pour the tahini sauce over top. Toss well, until everything is coated with the sauce. Serve right away, sprinkled with za’atar and garnished with the reserved cilantro leaves.