Prepare the Meat: Place the hog’s head (or substitute cuts) in a large stockpot. Cover with water and bring to a boil. Skim off any foam that forms.
Add Aromatics: Add onions, celery, garlic, bay leaves, peppercorns, and salt. Reduce heat to a simmer and cook for 3-4 hours, until the meat is tender and falls off the bone.
Strain and Separate: Remove the meat from the pot and strain the cooking liquid. Reserve the liquid.
Shred the Meat: Pick the meat from the bones, discarding any gristle or excess fat. Chop the meat finely.
Season and Combine: In a large bowl, mix the shredded meat with cayenne pepper, allspice, cloves, parsley, and green onions. Taste and adjust seasoning as needed.
Mold the Cheese: Line a loaf pan with plastic wrap. Place the meat mixture into the pan, pressing firmly to compact it. Pour reserved cooking liquid over the mixture to bind it, adding gelatin if desired.
Chill: Refrigerate for at least 6 hours or overnight until firm.
Serve: Slice and serve cold with crackers, pickles, or mustard.