Slice the chicken breast into thin, even strips.
In a small bowl, whisk together the cumin, coriander, turmeric, garlic powder, sea salt, and black pepper.
Toss the chicken strips with the spice mixture until thoroughly and evenly coated.
Heat the extra virgin olive oil in a large skillet over medium-high heat.
Add the chicken to the skillet and sear for 6 to 8 minutes, turning occasionally, until the exterior is golden brown and the internal temperature reaches 165°F.
While the chicken cooks, dice the cucumber and tomato, and finely mince the red onion.
In a separate bowl, combine the cucumber, tomato, and onion with the lemon juice to create a fresh salad.
Place the warm cooked brown rice in the base of a serving bowl.
Arrange the spiced chicken and the fresh vegetable salad over the rice.
Drizzle the tahini over the top and serve immediately.