In a small bowl, whisk together the ground cumin, coriander, turmeric, garlic powder, sea salt, and black pepper to create the shawarma spice blend.
Slice the chicken breast into thin, bite-sized strips and toss thoroughly with the spice blend until every piece is evenly coated.
Heat the extra virgin olive oil in a non-stick skillet over medium-high heat and sear the chicken for 5 to 7 minutes, stirring occasionally, until golden brown and cooked through.
While the chicken is cooking, prepare the sauce by whisking the plain Greek yogurt, tahini, and lemon juice together in a small ramekin until the texture is smooth.
In a separate small bowl, combine the diced English cucumber, halved cherry tomatoes, and finely diced red onion to create a quick fresh salad.
Place the warm, cooked basmati rice in the center of a serving bowl and arrange the spiced chicken and the fresh vegetable salad on top.
Finish the dish by drizzling the creamy tahini-yogurt sauce over the chicken and vegetables before serving immediately.