Prep the chicken: If using rotisserie, shred or chop it into bite-size pieces. If cooking from scratch, season lightly and cook until done, then cool and chop.
Rinse the chickpeas: Drain and rinse under cold water to remove excess starch and salt.
Pat dry for better texture.
Chop the veggies: Dice the cucumber and bell pepper, halve the tomatoes, and finely slice the red onion.
Make the dressing: In a small bowl or jar, whisk together olive oil, lemon juice, Dijon, garlic, and honey. Add salt, pepper, and red pepper flakes. Taste and adjust.
Toss the base: In a large bowl, combine chicken, chickpeas, cucumber, tomatoes, bell pepper, red onion, and herbs.
Add the dressing: Pour over the salad and toss gently until everything is evenly coated.
Finish and serve: Fold in feta and avocado, if using.
Serve over greens or mix the greens right into the bowl.
Let it rest (optional): For deeper flavor, cover and chill for 15–30 minutes before serving.