Pig's Head Terrine is a classic French dish made from slow-cooked pig's head, which is then shredded and mixed with herbs and spices. The mixture is then pressed into a terrine mold and chilled until set. The result is a rich and flavorful terrine that is perfect for serving as an appetizer or as part of a charcuterie board. This recipe also includes a recipe for homemade mustard, which adds a tangy and spicy kick to the terrine.