Combine soy sauce, oyster sauce, lime juice and sugar in a small bowl.
Heat oil in a large non-stick frying pan over medium heat. Add garlic and chilli and stir-fry 30 seconds. Increase the heat and add the spring onion, capsicum, snow peas, eggplant, mushroom and ginger and stir-fry 2 minutes. Add bok choy and stir-fry until wilted, about 1 minute. Add soy mixture and stir-fry until all the vegetables are tender-crisp, about 1 minute. Stir in basil and serve at once.