Heat iron wok. When very hot, add oil, and fry long beans till tender. Sprinkle a little water to avoid burning. Remove and drain.
Heat oil and fry garlic till very lightly browned. Add spicy soy bean paste, pork and prawns, and stir fry till pork changes color. Add A, then fried long beans. Continue cooking over low heat for 1 to 2 minutes. Remove and serve immediately.