Bulgogi is thinly sliced beef (typically ribeye or sirloin) marinated in a sweet-savoury mixture of soy sauce, sugar, sesame oil, garlic, pear or kiwi (enzymatic tenderiser), and green onion, then grilled over charcoal or on a domed grill pan.
Tenderising with fruit
The marinade uses Asian pear or kiwi juice. Both contain protease enzymes (bromelain in kiwi, cysteine protease in pear) that break down muscle fibre proteins, producing the characteristic soft texture. Marinate maximum 2 hours — longer and the meat becomes mushy.
Thickness
Bulgogi is sliced 2–3 mm: thin enough to cook in under 2 minutes at high heat, thick enough to stay juicy. Partially freeze the beef before slicing to make paper-thin cuts achievable without a deli slicer.