2Pound the pork slices in a ziploc bag using a meat pounder.
3In a pot, add olive oil and pork lard. Once melted, add the sliced onions and stir.
4Add garlic, cinnamon, smoked paprika, cayenne pepper, salt, and pepper. Stir and cook for about a minute.
5Remove about a third of the onion mixture.
6Add crushed tomatoes and beer to the pot and bring to a boil.
7Add white wine and bay leaves. Bring to a boil again and cook for four minutes.
8Remove bay leaves and use an immersion blender to create a smooth sauce.
9Bring the sauce to a simmer and gently add the pork slices one at a time, ensuring they don't clump together.
10Partially cover the pot and simmer for 35-40 minutes.
11Assemble the sandwich by spreading some sauce on the bun, then adding some of the previously removed onions, the pork, and topping with remaining sauce.