In a small bowl, whisk together half the olive oil, lemon juice, minced garlic, cumin, coriander, paprika, turmeric, salt, and pepper.
Cut the chicken breast into bite-sized pieces and toss in the spice marinade until thoroughly coated.
Heat the remaining olive oil in a large skillet over medium-high heat and sauté the chicken for 6-8 minutes until golden brown and cooked through.
While the chicken cooks, dice the cucumber, halve the cherry tomatoes, and thinly slice the red onion, then toss them together in a small bowl.
In a separate small dish, stir together the Greek yogurt and dried oregano to create a simple garlic-herb sauce.
Assemble the bowl by placing the warm cooked brown rice at the base.
Top the rice with the spiced shawarma chicken and the fresh vegetable salad.
Drizzle the creamy yogurt sauce over the entire bowl and serve immediately.