The standard version I make doesn't have the feta and tomatoes - add an egg instead. Inspiration to add them is from turkey burger recipe himself makes.
Mince 225g cooked chicken and one small onion. Add 40g breadcrumbs, 25g chopped feta, 4 chopped sun dried tomatoes and 2tbsp chopped parsley (OR coriander). Divide into 8 portions and shape into burgers. Fry for 5 minutes on each side.