Boil the pork knuckle. Place the knuckle in the multicooker bowl, add cold water to cover the meat completely. Add onion, carrot, peppercorns and allspice. Salt and cook in the "soup" mode for 120 minutes. Then add the bay leaf and cook for another 30 minutes.
Rub the cooked knuckle with spices. Remove the cooked knuckle from the water and cool. Make a cut on the side and carefully remove the bone. Distribute the chopped garlic evenly over the meat. The knuckle should lie skin side down. Sprinkle with paprika, grain mustard and black pepper, rub them into the meat.
Form a "rectangle" of pork. Take a container of a suitable size and put the knuckle in it, add a couple of spoons of the broth in which the knuckle was cooked. Disposable foil forms or, for example, a plastic container will do. Cover with a flat board or lid of a suitable size. You can put another container or form on top. Then press down the resulting structure with a weight and put it in the refrigerator. Keep the knuckle under pressure for 24 hours.