In a medium bowl, whisk together the olive oil, half the lemon juice, minced garlic, cumin, paprika, turmeric, cinnamon, salt, and pepper.
Slice the chicken breast into thin strips and toss in the marinade until thoroughly coated.
Heat a non-stick skillet over medium-high heat and cook the chicken for 6-8 minutes, turning occasionally, until golden brown and cooked through.
While the chicken cooks, dice the cucumber, halve the cherry tomatoes, and finely chop the red onion and parsley.
In a small ramekin, stir together the Greek yogurt with the remaining lemon juice and a pinch of salt to create the sauce.
Place the warm cooked brown rice in a bowl and top with the seared shawarma chicken and the fresh vegetable salad.
Drizzle the yogurt sauce over the top and garnish with fresh parsley before serving.