Butter Mandu (Butter Dumplings)

Place the cabbage, ginger and garlic in the bowl of a food processor and pulse until finely chopped. Place the cabbage mixture in a large bowl. Using your hands, fold the ground pork into the cabbage mixture just enough to combine. Evenly sprinkle it with the salt and fold it in. Gently fold the butter into the mixture until thoroughly combined. To assemble the mandu, place about 2 tablespoons of the filling in the center of each wrapper. Be careful not to overfill or the filling could leak while cooking. (If your wrappers are small, decrease the amount of filling per dumpling; the mandu should be full but not hard to close.) Dip your fingertip in a glass of water and paint the edge of the wrapper. Fold the wrapper over to form a half-moon and pinch the edges together to seal. (This is the easiest fold, for simplicity's sake, but you can fold your mandu in a number of fancy ways, like the pros do.) Mandu can be cooked right away or frozen for later (see below).