The three cups are sesame oil, soy sauce and rice wine, used in roughly equal measure with no water at all. As the chicken cooks they reduce onto the meat until every piece is coated in something dark, salty and faintly sweet.
Fry the ginger slowly at the start until the edges crisp: it is what gives the dish its backbone. The basil goes in off the heat at the very end so it wilts in the residual steam rather than turning black.
