1. Preheat your grill pan over medium-high heat.
2. Season the chicken breasts with salt and pepper.
3. Grill the chicken for 6-7 minutes on each side, or until fully cooked. Let it rest for a few minutes, then slice.
4. In a large mixing bowl, combine cherry tomatoes, cucumber, red onion, kalamata olives, and feta cheese.
5. In a small bowl, whisk together olive oil, red wine vinegar, dried oregano, minced garlic, salt, and pepper.
6. Pour the dressing over the salad and toss to combine.
7. Top the salad with the sliced grilled chicken and serve immediately.