Step 1: Prepare the Chicken: Preheat grill to medium-high heat. Rub chicken breasts with 1 tablespoon olive oil, dried oregano, salt, and pepper. Grill for 6-8 minutes per side, or until cooked through and internal temperature reaches 165F (74C). Let cool slightly, then dice or shred. Alternatively, chicken can be cooked in a pan on the stovetop, or baked in the oven at 375F (190C) for approximately 20-25 minutes.
Step 2: Prepare the Vegetables: Wash and chop the cucumber, bell pepper, and cherry tomatoes. Thinly slice the red onion. Pit and halve the Kalamata olives.
Step 3: Make the Dressing: In a small bowl, whisk together 1/4 cup olive oil, lemon juice, red wine vinegar, minced garlic, dried oregano, Dijon mustard, salt, and pepper. Adjust seasoning to taste.
Step 4: Assemble the Salad: In a large bowl, combine the diced or shredded grilled chicken, chopped cucumber, bell pepper, cherry tomatoes, Kalamata olives, red onion, and crumbled feta cheese.
Step 5: Dress the Salad: Pour the lemon herb dressing over the salad ingredients. Toss gently to coat everything evenly.
Step 6: Serve: Serve immediately, or chill for later enjoyment. For best flavor, allow the salad to sit for at least 15 minutes before serving to allow the flavors to meld.
Optional Tips: For a creamier dressing, add a tablespoon of Greek yogurt. Substitute grilled halloumi for chicken for a vegetarian option. Consider adding sun-dried tomatoes or artichoke hearts for added flavor.