Steps
1. In a bowl, mix olive oil, lemon juice, oregano, salt, and pepper.
2. Marinate the chicken breast in the mixture for 15 minutes.
3. Heat a grill pan over medium heat and cook the chicken for 6-7 minutes on each side until fully cooked.
4. Let the chicken rest for 5 minutes, then slice thinly.
5. In a salad bowl, combine mixed greens, cherry tomatoes, cucumber, and feta cheese.
6. Top the salad with the sliced grilled chicken.
7. Drizzle any remaining marinade or a light vinaigrette over the salad and serve.