Heat grill to medium-high heat until it becomes very hot.
Form meat into 4, 1 inch patties.
Season patties generously with coarsely ground salt and pepper.
Lightly coat tomatoes and arugula with extra virgin olive oil, salt and pepper.
Arrange patties on the griddle and cover.
Cook over moderately high heat for 3-4 minutes per side.
Flip the patties and cook covered for another 2 minutes longer.
Top patties with mozzarella and cook for 1 minute covered until cheese melts lightly.
Brush King’s Hawaiian Hawaiian Sweet Hamburger Buns with extra virgin olive oil and grill for 20 seconds on each side.
Place patties on bun and top with arugula and tomatoes.