Marinate the Pork:

1. In a small bowl, whisk together the pineapple juice, olive oil, garlic, chipotle powder, oregano, cumin and salt. Pour into a large zip-seal plastic bag. Add the pork chops, seal shut, and shake to coat the chops with marinade. Place in the refrigerator to marinate for at least 2 hours, or preferably overnight.

Prepare the Salsa:

1. Preheat a lightly-oiled grill to medium-high heat.
2. Arrange the pineapple spears on the grill and cook for 3-5 minutes on each side, or until lightly charred around the edges. Transfer to a cutting board and set aside to cool for a few minutes.
3. In a medium bowl, combine the remaining salsa ingredients. Roughly chop the pineapple, and add to the bowl. Toss to combine and set aside to let the flavours mingle while you finish the preparations.

Grill the Pork and Assemble Tacos:

1. Place the pork chops on the grill and cook over direct heat for about 5-7 minutes per side, or until a meat thermometer registers an internal temperature of 160F. Transfer to a cutting board to rest for 5 minutes, then roughly chop into bite-sized chunks.
2. To assemble the tacos, arrange the tortillas on four serving plates. Spoon chopped pork onto the tortillas, dividing evenly, and then top each one with a generous amount of pineapple salsa.
3. Serve immediately, with the remaining toppings on the side so that everyone can garnish their tacos as they wish.