In a medium bowl, working gently, mix ground beef with all burger ingredients except buns.
Divide the mixture into 4 quarters and lightly form into patties about 1" thick.
Place patties on an oiled outdoor grill (or you can cook in a skillet) and cook, turning once, about 10-15 minutes or until cooked to desired doneness. You can add the cheese slices onto the burgers a few minutes before they are done to melt if desired.
Meanwhile, open buns and toast on grill until lightly browned. Place cooked burgers on buns and top with desired toppings.