Once grill is hot, place one ground lamb ball mixture on griddle, place one pita bread on top and smash using a spatula or a burger press until flat. Let the pressed lamb mixture cook for about 5-6 minutes or until crispy then flip and cook for an additional 1-2 minutes. Repeat this until all the lamb mixture is used.
Top with tzatziki sauce, cherry tomatoes, mini cucumbers arugula, pickled onions, and more feta.