In a medium mixing bowl, whisk together olive oil, lemon juice, minced garlic, dried oregano, salt, and pepper.
Add chicken pieces to the marinade and toss to coat; marinate for at least 10 minutes.
Heat a large non-stick skillet over medium-high heat.
Add the chicken to the skillet (discarding excess marinade) and cook for 8 to 10 minutes, stirring occasionally, until the chicken is golden brown and reaches an internal temperature of 165°F.
To assemble, divide the cooked rice among four bowls.
Top each bowl with equal portions of the cooked chicken, cucumber, cherry tomatoes, red onion, and olives.
Garnish each bowl with crumbled feta cheese and a dollop of tzatziki sauce.
Sprinkle with fresh parsley and serve immediately.