Prep the chicken: Use cooled cooked chicken. Chop or shred into bite-size pieces.
Rotisserie chicken works great.
Chop the vegetables: Dice cucumber, halve tomatoes, and thinly slice red onion. Dice avocado last to keep it fresh.
Make the dressing: In a small bowl, whisk olive oil, lemon juice, Dijon, honey, garlic, salt, and pepper until smooth and glossy.
Toss the base: In a large bowl, combine chicken, cucumber, tomatoes, onion, and herbs. Drizzle most of the dressing over and toss gently.
Add avocado: Fold in avocado and feta (if using).
Add the rest of the dressing as needed. Taste and adjust salt and pepper.
Serve: Spoon over greens or enjoy as-is. For extra crunch, add toasted pumpkin seeds or crushed pita chips on top.