Make the dressing: In a small bowl, whisk olive oil, lemon zest, lemon juice, red wine vinegar, Greek yogurt or mayo, Dijon, garlic, oregano, salt, and pepper until smooth and creamy.
Prep the veggies: Dice the cucumber and bell pepper, halve the tomatoes, thinly slice the red onion, and slice the olives.
Combine the base: In a large mixing bowl, add the chicken, cucumber, tomatoes, bell pepper, red onion, and olives.
Add feta and herbs: Sprinkle in crumbled feta and chopped parsley or dill.
Toss with dressing: Pour the dressing over the salad and gently fold until everything is evenly coated.
Taste and adjust salt, pepper, or lemon.
Chill briefly (optional but recommended): Let the salad rest in the fridge for 20–30 minutes to let flavors mingle.
Serve: Spoon over crisp romaine or butter lettuce, wrap in lettuce cups, or enjoy as is. A squeeze of fresh lemon right before serving brightens it up.