Combine the ground cumin, ground coriander, ground turmeric, garlic powder, sea salt, and black pepper in a small bowl to create the shawarma spice blend.
Slice the chicken breast into bite-sized strips and toss them in the spice mixture until every piece is thoroughly and evenly coated.
Heat the olive oil in a large skillet over medium-high heat and sear the chicken for 6 to 8 minutes until it is browned and cooked through.
While the chicken is cooking, prepare the fresh salad by mixing the diced cucumber, halved cherry tomatoes, and thinly sliced red onion.
In a small ramekin, stir the lemon juice into the Greek yogurt until the mixture is smooth and reaches a drizzling consistency.
Assemble the bowl by placing the warm cooked brown rice at the bottom and layering on the spiced chicken and the fresh vegetable salad.
Finish the dish by drizzling the creamy lemon-yogurt sauce over the top and garnishing with a sprinkle of fresh parsley.