Whisk the soy sauce, honey and 2 tbsp water together in a small bowl, making sure the honey dissolves.
Heat the vegetable oil in a large wok over a high heat. When the air above it is shimmering, add the garlic and stir-fry for just 20 seconds, until it smells aromatic. Add the bok choi and stir-fry very briskly for 1 minute, making sure the garlic combines with the bok choi. Pour the honey and soy mixture in and add the chilli flakes.
Continue to stir-fry until the leaves of the bok choi have wilted – the stems will still be quite crisp but glossy and succulent. Drizzle with the sesame oil and serve immediately.