Preheat the oven to 425°F (220°C). Line a baking sheet with parchment paper.
Remove the leaves from the cauliflower and cut it into florets. Place the florets in a mixing bowl.
In a small bowl, whisk together olive oil, cumin, smoked paprika, turmeric, cinnamon, cayenne pepper, salt, and black pepper. Pour this mixture over the cauliflower florets and toss until well coated.
Spread the seasoned cauliflower evenly on the prepared baking sheet and roast in the preheated oven for 25-30 minutes, or until golden brown and tender, tossing halfway through.
While the cauliflower is roasting, rinse the quinoa under cold water. In a medium saucepan, combine quinoa and vegetable broth. Bring to a boil, then reduce heat to low, cover, and simmer for 15 minutes or until the quinoa is fluffy.
In a bowl, combine the tahini, lemon juice, minced garlic, and water. Whisk until smooth. Adjust seasoning with salt, and add more water if a thinner consistency is desired.
Once the cauliflower and quinoa are done, assemble the bowls: start with a base of quinoa, top with roasted cauliflower, cherry tomatoes, cucumber, red onion, and parsley. Drizzle tahini sauce on top.
Serve immediately and enjoy your delicious Cauliflower Shawarma Bowls!