Teriyaki McBurger

Minced pork
Egg
1/4 onion, chopped
1/2 Tbsp panko
1/2 Tbsp milk
Black pepper
Cooking fat/oil
1/2 Tbsp shoyu
1/2 Tbsp mirin
1/2 Tbsp sake
1/2 Tbsp honey
1/2 tsp garlic, minced
1/2 tsp ginger, minced
1/2 tsp potato starch, diluted in water
1 Tbsp mayo
Lemon juice
Lettuce
Buns