Slice the chicken breast into thin strips and toss in a bowl with the cumin, coriander, turmeric, garlic powder, sea salt, and black pepper until evenly coated.
Heat the olive oil in a large skillet over medium-high heat and sear the chicken strips for 5-7 minutes until they are golden brown and cooked through.
Remove the chicken from the skillet and set aside; in the same pan, add the cauliflower rice and sauté for 3-4 minutes until tender.
Prepare the base of the bowls by dividing the sautéed cauliflower rice and cooked quinoa between them.
Top the grains with the diced cucumber, halved cherry tomatoes, and the crispy shawarma chicken.
In a small bowl, whisk together the tahini and lemon juice with a teaspoon of warm water to reach a pourable consistency, then drizzle over the bowls and garnish with fresh parsley.