Stir the pork fat, ground pork, onions, water, cloves, and nutmeg together in a large pot. Season to taste with salt and pepper. Bring to a boil over medium-high heat, then reduce heat to medium-low, and simmer until the pork is tender, at least 1 1/2 hours. Use a potato masher to mash the pork mixture every 15 minutes as it cooks.
The longer you simmer the gorton, the better the flavor will be. Add water as needed to keep the mixture from boiling dry. When you're ready to stop cooking, let the liquid reduce as much as possible without letting it burn. Refrigerate the gorton overnight. Remove and discard the fat layer, or stir it into the meat for a creamier spread.