Slice the chicken breast into thin, bite-sized strips.
In a small bowl, toss the chicken with olive oil, garlic powder, cumin, smoked paprika, sea salt, and black pepper until evenly coated.
Heat a non-stick skillet over medium-high heat and add the seasoned chicken.
Sauté the chicken for 6-8 minutes, stirring occasionally, until golden brown and cooked through.
While the chicken cooks, whisk together the non-fat Greek yogurt and lemon juice in a small ramekin to create the sauce.
Place the warm cooked brown rice in the bottom of a serving bowl.
Arrange the sautéed chicken, diced cucumber, diced tomato, and sliced red onion over the rice.
Drizzle the lemon-yogurt sauce over the entire bowl and serve immediately.