How to Make It
Put the fermented black beans in a bowl and cover with water. Let stand for 15 minutes. Drain and coarsely chop the beans.
In a food processor, combine the black beans, garlic and ginger and pulse until finely chopped. Add the chile paste, vinegar, soy sauce, sesame oil and sugar and blend well.
On a work surface, pound the pork slices 1/8 inch thick. Lay one-fourth of the pork slices in a large, shallow dish and coat with one-fourth of the black bean marinade. Repeat with the remaining pork and marinade for three more layers. Cover and refrigerate for up to 24 hours.
Light a grill or preheat a grill pan. Remove the pork from the marinade, leaving just a thin coating on the meat. Brush the pork with oil and grill over moderate heat, turning every 2 minutes, until nicely charred and cooked through, about 6 minutes.
Chinese fermented black beans and gochujang are available at Asian markets and from amazon.com. Or substitute an equal amount of Chinese black bean sauce or any kind of Asian chile paste.