In a large bowl, combine the cubed chicken with olive oil, minced garlic, lemon juice, oregano, paprika, thyme, cumin, salt, and pepper. Mix well to ensure all chicken pieces are coated.
In a separate bowl, whisk together the Greek yogurt, grated cucumber, lemon juice, dill, garlic, olive oil, salt, and pepper until thoroughly blended. Set this tzatziki aside.
Heat a non-stick skillet over medium heat. Once hot, add the seasoned chicken in a single layer. Cook for approximately 8–10 minutes, turning occasionally until the chicken is golden and cooked through, reaching an internal temperature of 165°F (74°C).
To assemble, place a generous scoop of cooked orzo or your choice of grain into four bowls. Top each with a portion of the sautéed chicken, diced cucumber, cherry tomatoes, sliced red onion, olives, and feta cheese.
Drizzle the tzatziki sauce over the bowls or serve it on the side. Garnish with lemon wedges for an extra zesty finish.