Did you know you could marinate chicken in feta brine? It works in the same way yoghurt does, tenderising the meat and keeping it moist.
Start by marinating the chicken. Add all of the ingredients to the bowl, mix well, then cover and leave to sit for at least an hour.
Meanwhile, make the green sauce. Add all the herbs, garlic, and liquids to a blender and blend until super smooth. Set to the side.
Cook the chicken in a hot skillet, griddle pan, or barbecue. Once it reaches 73 C internal temperature, and it's nicely charred all over, remove from the pan and let it rest for a few minutes. Slice up.
Toast the ciabatta in the same chicken pan.
Pat dry the feta cheese and slice into cubes, then lightly coat in seasoned flour. Coat in egg, then panko, then egg again, and panko one more time. Repeat with remaining cubes.
Preheat the oil to 180 C. Carefully drop in the feta and fry until deep golden brown. Remove from the oil and place on a rack to drain.
Build the sandwich. Green sauce, then chicken, tomato, fried feta, a drizzle of honey, cucumber, pickled onion, then tapenade on the top slice. Enjoy!