To a large bowl, add the first 9 ingredients (pork through the salt and pepper to taste). Form the mixture into 4 equal patties and set aside.
Heat outdoor grill or grill pan to medium-high heat.
Grill the burgers for 5 to 7 minutes per side, or until cooked through. Remove from the grill and place each patty on a piece of lettuce. Top with the onion through the tomato and then place the remaining lettuce leaves on top. Serve right away.