Heat wok and add oil for deep-frying. When oil is ready (the temperature should be between 360 – 375 degrees), carefully slide in the Crab Rangoon, taking care not to overcrowd the wok. Deep-fry until they are golden brown, about 3 minutes, turning once. Remove with a slotted spoon and drain. Serve hot with Sweet and Sour Sauce or Chinese Hot Mustard.