Cut pork into thin slices. Prepare 200 cl. tamarind  Mix in the crushed garlic, sambal oelek, grated ginger and cornflour. add salt and marinade pork in this mix for at least 1 hour. Stir fry the pork in a wok for 5 - 10 min. until browned. Remove from wok. Stir fry chopped spring onion and chillis for 3 min., add chopped tomatoes, pork and ketjap manis, heat through and serve hot.