Pat the boneless, skinless chicken breasts dry with paper towels. Heat a skillet or grill pan over medium-high heat, drizzle with olive oil, and season with oregano, garlic powder, salt, and pepper. Cook for 6-7 minutes per side until the internal temperature reaches 165°F.

Let the chicken rest for 5 minutes before slicing.

In a large mixing bowl, combine chopped cucumber, halved cherry tomatoes, diced red onion, crumbled feta cheese, and pitted Kalamata olives. Drizzle with fresh lemon juice and gently toss.

Divide the salad mixture among serving bowls, top each bowl with sliced chicken, and sprinkle with freshly chopped parsley. Serve immediately.