Gently combine the beef, egg, bread crumbs, and salt and pepper together in a bowl until all burger patty ingredients are mixed completely. Divide mixture equally into 4 balls. Make a ‘well’ in the burger ball, then fill the well with desired amount of Nikos Feta. Fold over the meat to cover the feta until the cheese is completely sealed inside. Then proceed to flatten the meat ball into a patty.
If making this recipe ahead of time, place the patties on a plate or in a container, cover, and chill them in the refrigerator until you are ready to grill. If grilling right away, place patties on grill and cook to your desired temperature.
Top burgers with a dollop of tzatziki sauce and feta cheese. Optional toppings are slices of tomato and cucumber.