Preheat the oven to 400°F/200°C.
To a large sheet pan, add cauliflower florets, chickpeas, red onion wedges. Drizzle with olive oil, then season with smoked paprika, ground cumin, garlic powder, and salt.
Roast in the preheated oven for 20-25 minutes or until the cauliflower florets are fork tender, then place under the broiler for 3-5 minutes for everything to crisp up but keep an eye on them. If you want the cauliflower crispier, place under the broiler for a few minutes.
Remove from the oven and allow to cool for 15-20 minutes.
As the cauliflower is being roasted, make the tahini dressing. In a bowl, combine tahini paste with lemon juice, water, garlic, and salt. Whisk until creamy but not too thick. Add more water if needed to thin it out.
To assemble the salad, add arugula to a large bowl, followed by the cooled roasted cauliflower, spicy chickpeas and onion. Drizzle with the dressing, and sprinkle with toasted sunflower seeds/pepitas and dried cranberries. Toss to combine and serve.