Special equipment: a mandoline
Mix soy sauce, sugar, mirin, sake, sesame oil, granulated garlic and lemon pepper together well in a bowl with a whisk. Pour marinade over beef and gently fluff the meat to work the marinade into it. Separate mixture into 4 portions and form into burger patties.
Heat a grill for cooking over medium-high heat. Grill patties to medium-rare (130 to 135 degrees F).
Toast brioche buns in a pan until golden brown. Fry 4 sunny-side up eggs and set aside.
Put patties on buns, then top with fried eggs, teriyaki sauce, wasabi mayo, fried onions, wasabi mayo and furikake.
Combine soy sauce, sugar, mirin and sake in a saucepan over medium heat. Cook until sugar is dissolved. In a separate bowl, mix cornstarch with 1/2 cup water to make a slurry. Add slurry to pot and bring to a boil. Remove from heat.
Mix mayo, wasabi, 1/4 cup water and salt to taste in a mixing bowl until smooth. Pour mixture into a small squeeze bottle or spread directly on buns.
Bring oil to 350 degrees F in a deep-fryer or Dutch oven.
Dip onions in flour and place in a wire basket to shake off excess. Fry onions until golden brown. Season immediately with salt to taste.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.
Recipe courtesy of Fukuburger, Las Vegas, NV