Make the dough: In a bowl, combine salt, flour and water. Knead into a smooth dough for 5 minutes. Cover with a cloth and set aside to rest for 1 hour. Knead the dough again for 3 minutes. Dig a hole in the center of the dough and then shape into a long log. Divide the log into small portions. Cut to round discs. Make the filling: Mix shrimp and pork with salt. Stir until the filling becomes sticky. Mince green onion and ginger. Mix with the filling. Place one tablespoon of filling in the center of your wrapper. Seal the dumpling. Steam the dumplings: Place the dumplings in a steamer and steam for 15 minutes over medium fire.