Summarize this article in one sentence.
Place the mustard seeds, bay leaves, and Allspice berries in a mortar and grind them together using a pestle. If you do not have a mortar and pestle, you could use the handle of a meat tenderizer or other utensil and a small dish, like a custard dish or ramekin. Similarly, you could place the spices in a resealable plastic bag, seal it, and crush them with a rolling pin. In a small mixing bowl, stir together the ground spices with the salt and pepper until each spice is evenly distributed. The spices can be mixed together with a spoon or fork. Set aside once combined.
Crush the mustard, bay leaves, and Allspice. Combine all the spices together.