Cook the quinoa according to package instructions using water or chicken broth until fluffy.
In a large bowl, toss the cubed chicken breast with 1 tablespoon of olive oil, oregano, garlic powder, salt, and pepper.
Heat the remaining tablespoon of olive oil in a large skillet over medium-high heat.
Add the chicken to the skillet and cook for 8 to 10 minutes, stirring occasionally, until the internal temperature reaches 165 degrees Fahrenheit.
While the chicken cooks, prepare the vegetables by dicing the cucumber, halving the tomatoes, and slicing the onion.
In a small bowl, whisk together the Greek yogurt and lemon juice to create a high-protein dressing.
Assemble the bowls by layering equal portions of cooked quinoa, sautéed chicken, and fresh vegetables.
Top with crumbled feta cheese and Kalamata olives, then drizzle with the yogurt dressing.