Preheat the oven to 425°F (220°C).
In a large bowl, combine cauliflower florets, olive oil, shawarma spice blend, and salt.
Spread the cauliflower on a baking sheet in a single layer.
Roast the cauliflower for 25-30 minutes, turning once halfway through.
While the cauliflower roasts, prepare the quinoa or couscous as per package instructions.
In a bowl, whisk together tahini, lemon juice, and water to create a drizzle.
Assemble the bowls with quinoa or couscous at the base, topped with roasted cauliflower.
Add cherry tomatoes, avocado slices, and drizzle with tahini sauce.
Garnish with fresh parsley and serve.