Eat this dish alone as a salad, as pita pocket sandwiches, or atop flatbread like a taco.
In a small skillet, toast the nuts over medium heat, stirring often, until fragrant and browned, 3 to 5 minutes. Transfer to a cutting board and let cool. Coarsely chop the nuts.
Shred or chop the chicken into bite-size pieces. (Reserve the skin and bones for stock.)
In a large bowl, whisk the yogurt, herbs, lemon juice, oil, garlic, oregano, and hot sauce. Season the dressing with salt and pepper. Mix in the cucumber, feta, celery, onion, tomatoes, and chicken. Season the chicken salad.
Arrange the salad on a platter or in a large shallow bowl. Top with the nuts, sliced pepperoncini, and olives. Serve the salad with piles of lettuce leaves for lettuce cups or with pitas and chopped lettuce for sandwiches.