1. Cut the rump steaks into thin slices across the grain. Mix a marinade from soy sauce, 50 ml sherry, potato starch and pepper and place the meat in it.
2. Meanwhile, wash the peppers and chili peppers, remove the seeds and cut into bite-sized pieces. Wash the spring onions and cut into 4 cm long pieces. Peel and chop the ginger, onion and garlic. Roughly chop the coriander.
3. Now drain the marinated beef, collecting the marinade. Mix this with chicken stock, oyster sauce, remaining sherry and a little sugar.
4. Heat some oil in a wok or pan on a very high heat and fry the meat until crispy, then remove from the wok and set aside
5. Heat some oil again and fry the garlic and ginger briefly. Add the peppers, spring onions and onions and fry. Stir frequently. Deglaze with the sauce mixture and allow to reduce slightly. Add the coriander, meat and peppers and cook briefly again.
6. To serve, arrange on plates and season again with pepper.