Rinse the beans and break off the ends; dry them thoroughly to reduce spattering during deep-frying. Rinse and mince the Szechuan mustard green. Wash the dried shrimp and soak them in sherry for 1 hour. Drain them, reserving the sherry. Mince the shrimp. Mix the sherry from the shrimp with the chicken broth, water, soy sauce and sesame oil. Reserve. Heat the oil in a wok (or deep pan) until a bamboo chopstick sizzles when put into the oil. Deep fry the beans in 5 or 6 batches, until they develop brown blisters and shrivel slightly. Remove them batch by batch; drain each batch and keep them warm while you remove all but 2 T oil from the pan. Heat the 2 T of oil until very hot and add the ground pork. Stir fry until it is broken up into very small pieces and no longer is pink. Add the minced shrimp and Szechuan mustard green. Stir for 30 seconds. Add the string beans and stir to mix well for about 15 seconds. Add the liquid ingredients, toss until the liquid is reduced to 2 tablespoons. Serve on a warmed platter.