In a small bowl, whisk together the ground cumin, coriander, turmeric, garlic powder, sea salt, black pepper, and olive oil.
Rub the spice mixture evenly over the chicken breast until fully coated.
Heat a non-stick skillet over medium-high heat and cook the chicken for 6-7 minutes per side until the internal temperature reaches 165°F.
While the chicken is cooking, prepare the sauce by whisking the tahini and lemon juice together, adding a teaspoon of water at a time until it reaches a smooth, drizzling consistency.
Dice the cucumber, halve the cherry tomatoes, and finely mince the red onion.
Once the chicken is finished, let it rest for 3 minutes before slicing it into thin strips.
Place the warm brown rice in a bowl and top with the sliced chicken Shawarma and the fresh vegetables.
Drizzle the tahini sauce over the entire bowl and garnish with chopped fresh parsley.