Stir-Fried Beef with Ginger and Spring Onion (Jiang Cong Chao Niu He / 姜葱炒牛河)

Slice the flank steak thin against the grain. Combine in a bowl with the soy sauce, oyster sauce, sesame oil, cornstarch, and bicarbonate of soda. Mix thoroughly until each slice is evenly coated. Rest at room temperature for 30 minutes. The surface of the beef will appear slightly tacky and pale where the cornstarch has bound.

Set the wok over the highest available heat and leave it until it begins to smoke. Add the oil and swirl to coat. Add the ginger julienne and fry, moving constantly, until fragrant and the edges begin to colour. The kitchen will fill with a sharp, clean ginger scent — this is the signal to proceed.

This is where the dish lives or dies. Add the marinated beef in a single layer across the wok. Do not stir immediately — allow each piece to sear against the metal for several seconds. If the beef steams rather than sears, the wok is not hot enough and the dish is already compromised. Once the underside is coloured, toss and stir rapidly until the beef is just-cooked with a faint pink at the centre; residual heat will finish it on the plate.

Add the oyster sauce and toss to coat every piece of beef. The sauce should cling in a glossy, even film — not pool at the base of the wok.

Add the spring onion lengths and toss once or twice — no more. They must retain their fresh colour and a slight bite. Transfer immediately to a warmed plate and serve at once.