Slice the Pork Loin thinly across the grain into cutlets or pound gently to an even thickness; season both sides with Salt and Black Pepper.
In a bowl combine minced Garlic, Dry White Wine, White Wine Vinegar, Sweet Paprika, a pinch of Piri-Piri (to taste), and a couple of Bay Leaves to make the marinade.
Pour the marinade over the pork, cover, and refrigerate for at least 2 hours or preferably overnight so the flavors deepen.
When ready to cook, remove the pork from the fridge and let it come close to room temperature while reserving the marinade; discard the bay leaves before using the marinade in the pan.
Heat a large skillet over medium-high heat and melt enough Lard to coat the surface.
Sear the pork slices in batches until nicely browned and cooked through, about 2–3 minutes per side; transfer cooked pork to a plate and keep warm.
Add the reserved marinade to the skillet, bring to a simmer, and reduce for a few minutes until slightly thickened and flavorful—taste and adjust seasoning with more salt or pepper if needed.
Split and lightly toast the Portuguese Papo-Seco Roll either in the oven or cut-side down in the skillet to absorb some of the sauce.
Spread a thin layer of Yellow Mustard on the roll, pile on the sliced pork, spoon some of the reduced pan sauce over the meat, close the sandwich, and serve immediately.
