You will need sliced pork of some sort, basic bread ingredients, olives, capers, butter, dried fruit, 1 beaten egg, and a functional kitchen.
Step 1: The Meat
Do everything you can to add flavor. I bury it in spices and let it pickle in the fridge overnight. Roast, water bath, or grill to an internal temperature of 145F. Then let it rest until cool. Slice as thin as you can and bag it to have ready. About 2 pounds is good.
But you can use ham if you want to be old-fashioned.