In a small bowl, whisk together the lemon juice, 0.5 tbsp of olive oil, garlic powder, cumin, smoked paprika, sea salt, and black pepper to create the shawarma marinade.
Place the chicken breast on a cutting board and slice into thin, even strips, then toss thoroughly in the lemon-herb marinade until well coated.
Heat the remaining 0.5 tbsp of olive oil in a large skillet over medium-high heat until it begins to shimmer.
Add the marinated chicken to the skillet and sear for 5-6 minutes, turning occasionally, until the edges are golden brown and the meat is cooked through.
While the chicken is cooking, combine the non-fat Greek yogurt and fresh parsley in a small ramekin to create a cooling herb sauce.
Assemble the bowl by placing the fluffy cooked quinoa at the base, then topping with the warm seared chicken, diced cucumber, and cherry tomatoes.
Drizzle the parsley-yogurt sauce over the top of the bowl and serve immediately while the chicken is tender and juicy.