Place pork, onion, cinnamon, and clove into a saucepan. Season with salt and pepper. Pour in enough water to just cover pork. Bring to a boil.
Reduce heat to medium-low and cook until water has nearly evaporated, about 1 hour. Stir occasionally to ensure pork cooks evenly.
Use a potato masher or wire whisk to break pork into thin strands. Pour off any remaining liquid, then spoon gorton into a serving bowl. Refrigerate until cold before serving.