Combine ½ cup pineapple juice (reserving the chunks), the chili powder, pork, and half the jalapeños in a large resealable plastic bag. Refrigerate for at least 1 hour and up to 4 hours. Remove the pork from the marinade, shake off the excess liquid, and season with salt.
Heat 1 tablespoon of the oil in a large skillet over medium-high heat. Cook the pork in batches until just cooked through, 3 to 4 minutes per side, adding the remaining tablespoon of oil between batches. Thinly slice.
Top the tortillas with the pork, pineapple chunks, onion, cilantro, cheese, and the remaining jalapeño.
Serve with the lime wedges.
Tasty. Very easy. A keeper.
