1.In ceramic dish, combine beef, oyster sauce and oil. Season to taste. Cover and chill for 10 minutes.
2.In a large saucepan of boiling water, cook noodles 3-4 minutes, until softened. Drain well and set aside.
3.Heat a large wok or char-grill on high. Cook beef in 2 batches, for 1-2 minutes each side, until browned.
4.To make dressing, whisk all ingredients together in a small jug. Set aside.
5.In a large bowl, toss noodles, pineapple, cucumber, snow peas and half dressing together. Just before serving, toss beef through noodle mixture. Drizzle with extra dressing. Serve salad topped with cashews, basil leaves and extra chilli.