Combine the vinegar, pineapple juice, pimenton, chile, salt, and pepper in a large resealable plastic food storage bag; mix well, then add the cutlets. Press the air out of the bag and seal; massage the marinade into the meat. Let sit for at least 10 minutes or up to an hour, while you make the salsa and warm the tortillas.
Combine the pineapple, cilantro, shallot, and jalapeño in a small bowl. Squeeze the lime juice into the bowl. Add salt to taste and mix well.
Warm the tortillas and wrap them in aluminum foil to keep warm.
Pour the oil into a large skillet set over medium-high heat. When it starts to shimmer, remove the cutlets from the marinade, shake off any excess, and place in the skillet. Sprinkle lightly with a little more salt, then cook until lightly browned on one side, 1 to 2 minutes. Turn them over, sprinkle lightly with salt, and cook until browned on the other side and just cooked throughout, another 1 to 2 minutes.
Turn off the heat and let the cutlets rest for a minute.
Lay the tortillas out on a plate. Place one cutlet on each tortilla. Top each with pineapple salsa, and eat.
Note: If your pork is too firm or chewy to easily fold up whole in the tortilla, feel free to cut it into strips or chunks.
Andrea Reusing is the creator of the restaurant Lantern in Chapel Hill, N.C., and author of the book Cooking in the Moment: A Year of Seasonal Recipes. In this installment of The Key 3, she shares with Lynne Rossetto Kasper the techniques behind three of her favorite recipes: Turnip Soup, Overnight Braised Short Ribs and Tomato Salad.