Slice the chicken breast into thin, bite-sized strips and place them in a medium mixing bowl.
Add the olive oil, lemon juice, minced garlic, cumin, coriander, turmeric, sea salt, and black pepper to the chicken, tossing well to coat evenly.
Heat a large non-stick skillet over medium-high heat and add the marinated chicken strips in a single layer.
Sear the chicken for 6-8 minutes, turning occasionally, until the exterior is golden brown and the meat is cooked through.
While the chicken cooks, dice the cucumber, halve the cherry tomatoes, and finely mince the red onion.
In a serving bowl, assemble the base by combining the warm cooked quinoa with the prepared cucumber, tomatoes, and onion.
Place the hot shawarma chicken over the quinoa and vegetable mixture.
In a small ramekin, whisk the tahini with a teaspoon of warm water until it reaches a pourable consistency, then drizzle it over the bowl.
Garnish with freshly chopped parsley and serve immediately.