Mix together the turkey, mint, onion, and spice. Form into patties then refrigerate about 30 minutes.
Make the sauce by adding the sauce ingredients together and set aside.
Grill the burgers either on a cast iron grill or on the outdoor grill. Cook on one side for 4 minutes, then turn and put the feta cheese on, cover and cook an additional 3 minutes or until the cheese is melted.
Toast the buns on the grill.
Put some sauce on each bun, then put the patties and any additional toppings you might like.
S@b