The marinade consists of Kikkoman Low Salt soy sauce, sugar, (can substitute some Splenda) minced garlic, freshly ground black pepper, freshed grated ginger, green onion sliced into little rounds, peanut oil, a touch of Asian sesame oil. Proportions to your taste, but be heavy on the sugar. Meat is marinated at room temp. for about a half hour. (It was only semi defrosted. It's easier to slice when it's partially frozen, and you want it very thin.) Although I started with a traditional marinade for bulgogi the recipe sort of veered off a bit since I didn't grill the meat and chose to stir fry it with bok choy and then thicken the resultant liquid.