Cook chicken according to Oven Roasted Chicken Breast recipe (Recipe link in notes section).
Once chicken is cook enough to handle, dice into small pieces.
Dice celery, celery leaves, green onions, and carrots.
In large bowl, add diced chicken, celery, green onions, carrots, feta cheese, Greek yogurt, mayo, buffalo sauce, salt, pepper, garlic powder, mustard powder, and lemon juice.
Cover and refrigerate for 1 hour before serving.
To serve, lay a piece of lettuce flat. Scoop 1 cup of chicken salad into the center of the lettuce and smooth out with knife.
Lay lettuce onto tortilla wrap and fold like a burrito.