NOTES: IF YOU CANNOT FIND DRY SAKE, SUBSTITUTE IT WITH DRY SHERRY. YOU CAN SUBSTITUTE FRESH GARLIC AND GINGER WITH 1/8 TEASPOON EACH GARLIC POWDER AND GROUND GINGER. FOR A MILDER SAUCE, REDUCE THE AMOUNT OF SRIRACHA. DICED ROASTED RED PEPPER MAY BE USED IN PLACE OF DICED ROASTED GREEN CHILES. HAVARTI CHEESE MAY BE REPLACED WITH MONTEREY JACK OR PEPPER JACK CHEESE. USE ONLY KING'S HAWAIIAN BRAND ORIGINAL SWEET HAMBURGER BUNS.
PREPARE MEAT: Place 1 lb ground beef into a medium mixing bowl. Grate one loaf of SPAM over the ground beef. Mix 6 tablespoons cold water with 1 1/2 tablespoons cornstarch then pour over mixture. Grate 1/4 cup sweet onions into bowl. Wearing kitchen gloves, combine the meat mixture, squeezing it through the fingers until well combined.
PREPARE PATTIES: Shape meat mixture into 6 equal patties, about 1-inch larger in width than King's Hawaiian Hamburger Buns. Place patties on a platter. Sprinkle each patty on each side with fine sea salt and freshly ground white pepper. Refrigerate patties until ready to grill.
PREPARE SAUCE: Whisk all of the sauce ingredients in a small mixing bowl. Transfer sauce mixture into a non-stick skillet over medium-high heat. Bring to a boil, stirring constantly until completely thickened. Reduce heat to lowest setting and cover, stirring occasionally to refresh consistency.
PREPARE BUNS: Lightly and evenly butter each separated flat surface of King's Original Hawaiian Sweet Hamburger Buns. Attach buttered cut sides together and return to the original bag until needed, to keep fresh.
PREPARE FIXINGS: Cook the bacon if using, until crisp (2 slices per burger). Slice the vegetables and pineapple to specifications. Immerse the onion slices in the sauce. Cover and let heat. Turn once. Remove when onions have softened slightly.
PREPARE GRILL: Preheat your grill to medium-high heat. Arrange patties on one side of the grill. Place pineapple slices on the other side of the grill. Turn each when dark grill-marks appear. Remove patties and pineapple when done to your satisfaction.
TOAST BUNS: Place buttered buns sliced-side down on grill, just until medium-toasted.
ASSEMBLE BURGERS: Turn the grilled pineapple rings in the heated sauce, until well-coated, then remove. Spoon or brush the prepared sauce evenly across each cut top bun portion. Turn the grilled patties in the sauce pan to coat. Place the cheese slices over patties. Cover saucepan until cheese is melted. Transfer patties onto the bottom bun halves. Stir the drained green chiles well into the sauce mixture. Continue assembling burgers with the bacon (optional), then pineapple, sliced onion, and lettuce. Spoon the sauce over the grilled side of each top bun. Place top buns over each assembled burger.
SERVE IMMEDIATELY with Hawaiian potato chips, Maui onion rings or fries, and enjoy!