Place all the ingredients into a 6 quart slow cooker and cook on low for 20 to 24 hours.
Once the meat is done cooking, carefully remove the it to a large bowl to collect the juices.
Pass the broth from the slow cooker through a colander and then transfer it to a medium saucepan. Bring that broth to a simmer over medium heat and let it reduce until there’s only about 4 cups left.
Meanwhile, carefully pick the meat from the head and tongue and discard everything that’s not obviously meat. You may, however, want to pass the scraps through a colander to collect all the juices that will have released during the picking process. Add those juices to the ones that are already in the saucepan.
Place the meat and reduced broth into the bowl of a stand mixer equipped with the paddle attachment and mix on low speed until the meat gets finely shredded and the mixture is evenly combined.
Alternatively, you could pull the meat by hand using 2 forks and then mix the broth right in with a large spoon.
Pour the meat mixture into a greased loaf pan or terrine mold (you could also use several individual pans) and refrigerate overnight.
To unmold, delicately run a thin blade around the terrine then slightly warm the bottom of your mold by dipping it in hot water for a few seconds. For easier unmolding, you could also line your pan with plastic film. However, note that this will invariably leave fine lines and wrinkles on the surface of your terrine.
Invert onto a plate or wooden board and garnish with fresh greens.
*Kindly ask your butcher to clean and cut the head into pieces for you
Homemade Head Cheese https://thehealthyfoodie.com/homemade-head-cheese/