Heat a wok over medium heat and add the oil. Add the beans and fry for about 8 minutes, stirring regularly, until the beans are very well cooked and slightly shrivelled. Remove the beans from the wok to drain, then remove most of the oil, leaving about 1 tablespoon for frying.
Return the wok to the heat and add the garlic, ginger, chilli and spring onions and fry in the oil for about a minute, until fragrant. Return the beans to the wok, season very well with salt and black pepper and toss to coat the beans in the fried aromatics. Remove to a plate to serve.
