Prepare the meat: In a medium bowl, combine the sliced beef with 2 tablespoons of light soy sauce, the chicken stock, sesame oil, white sugar, and cornflour. Use your hands to massage the marinade into the meat until every slice is coated. You should feel the mixture become slightly tacky as the cornflour begins to work. Set aside for at least 15 minutes at room temperature. The meat will look glossy and feel silky to the touch.

Make the sauce: In a small bowl, whisk together the 3 tablespoons of light soy sauce, dark soy sauce, oyster sauce, white sugar, and the cornflour slurry (cornflour mixed with water). Stir until the sugar has dissolved and the cornflour is fully incorporated. The sauce should be a deep, rich brown colour with a smooth, thin consistency.

Preheat your wok or pan: Place a large wok or a heavy-based frying pan over the highest heat your hob can manage. Add 2 tablespoons of oil and swirl it around. You will know it is ready when the oil begins to shimmer and a wisp of smoke rises from the surface. This is the critical moment for achieving a good sear.

Sear the beef: Carefully add the marinated beef to the wok in a single layer. Do not stir it immediately. Let it sear undisturbed for a full 90 seconds. You will hear a loud, satisfying sizzle, and the edges of the meat will begin to turn a deep brown. Once seared, toss the meat vigorously for another 60 seconds until it is cooked through but still tender. The beef should smell deeply savoury and caramelised. Remove the beef from the wok and set it aside on a plate.

Cook the vegetables: Reduce the heat to medium-high and add the remaining 1 tablespoon of oil. Add the sliced onion and carrot batons first, stirring constantly for 2 minutes. The carrot should brighten in colour and the onion will become translucent. Add the bell pepper strips and cook for another minute. They should remain slightly crunchy, with a vibrant colour and a fresh, sweet aroma.

Add the aromatics: Push the vegetables to the sides of the wok, creating a well in the centre. Add the minced garlic and grated ginger. Stir them in the oil for about 30 seconds until they become fragrant. The garlic should turn a pale gold, and the smell will become intensely aromatic.

Combine and sauce: Return the seared beef to the wok, along with any resting juices. Pour the prepared sauce over the top. Increase the heat to high again and toss everything together vigorously for about 60 to 90 seconds. As the sauce heats, it will thicken and become glossy, clinging to the meat and vegetables. The sound will change from a watery sizzle to a thicker, stickier one. The final dish should be glistening, with no excess liquid pooling at the bottom of the wok.

Rest and serve: Transfer the stir fry to a warmed serving platter. Let it rest for 2 minutes before serving. This brief rest allows the sauce to set slightly and the flavours to meld. The final dish should look vibrant, with the dark, glossy sauce contrasting against the bright vegetables and tender slices of beef.