1. Arrange the sliced beef on two serving plates.
2. Heat a wok over a high heat and add the groundnut oil. When the oil starts to smoke, add the dried chillies, cloves, fennel, star anise and Sichuan peppercorns, and stir-fry for a few seconds. Add the green chillies and stir-fry for a few seconds, then add the chilli oil and lemon juice and season with salt.
3. Pour the hot oil over the beef slices and serve immediately.