Season chicken breasts with salt and pepper.
Grill over medium heat until cooked through (about 6-7 minutes per side). Let it rest, then slice.
In a large bowl, combine mixed greens, cherry tomatoes, cucumber, and red onion.
Add sliced chicken, feta cheese, and Kalamata olives on top.
Whisk together olive oil, lemon juice, minced garlic, dried oregano, salt, and pepper.
Drizzle the dressing over the salad and gently toss to combine.
Serve immediately, garnished with additional herbs or lemon zest if desired.