Preheat your oven to 425°F (220°C). Line a baking sheet with parchment paper.
In a large mixing bowl, combine the cauliflower florets with olive oil and spices. Toss until well coated.
Spread the seasoned cauliflower on the prepared baking sheet in a single layer. Roast for 25-30 minutes, stirring halfway through.
While the cauliflower is roasting, bring vegetable broth or water to a boil in a saucepan. Stir in the rinsed quinoa, lower the heat to a simmer, cover, and cook for about 15 minutes.
Remove the quinoa from heat, let it sit covered for 5 minutes, then fluff with a fork.
In a bowl, whisk together tahini, lemon juice, and a few tablespoons of water until smooth. Adjust the consistency as needed, and season with salt.
To assemble the bowls, divide the cooked quinoa among four bowls and top with roasted cauliflower, cherry tomatoes, cucumber, red onion, and parsley.
Drizzle the tahini sauce over the bowls and serve immediately.