In a medium bowl, whisk together the olive oil, half of the lemon juice, cumin, coriander, turmeric, garlic powder, sea salt, and black pepper.
Slice the chicken breast into bite-sized strips and toss in the spice marinade until every piece is well coated.
Heat a non-stick skillet over medium-high heat and cook the chicken for 6 to 8 minutes until it is golden brown and cooked through.
While the chicken cooks, toss the diced cucumber, halved cherry tomatoes, and sliced red onion with the remaining lemon juice and fresh parsley.
Warm the pre-cooked brown rice and place it at the base of a serving bowl.
Top the rice with the cooked shawarma chicken and the fresh vegetable salad.
Finish with a dollop of Greek yogurt on top before serving for a cooling contrast.