Slice the chicken breast into thin, bite-sized strips.
In a small bowl, whisk together 1 tsp of olive oil with the cumin, coriander, turmeric, garlic powder, sea salt, and black pepper.
Toss the chicken strips in the spice mixture until evenly coated.
Heat the remaining 1 tsp of olive oil in a skillet over medium-high heat and sauté the chicken for 6-8 minutes until golden brown and cooked through.
Prepare the salad by dicing the cucumber, tomatoes, and red onion, then tossing them with the lemon juice.
In a small ramekin, stir together the Greek yogurt and tahini, adding a teaspoon of water if needed to reach a pourable consistency.
Place the cooked basmati rice in a bowl, top with the warm shawarma chicken and the fresh vegetable salad.
Drizzle the yogurt-tahini sauce over the top before serving.