Stem and seed the dried chiles and place them in a microwave-safe bowl. Cover with water and microwave at high power until softened, about 3 minutes.
Let cool slightly, then drain and transfer to a food processor. Add the chipotle chilis, orange juice, lime juice, vinegar, anise seeds, oregano, cumin, ground cloves, sugar and garlic powder. Blend until smooth.
Transfer the marinade to a saucepan. Add the 2 tablespoons of oil and cook over moderate heat, stirring constantly, until very thick, about 5 minutes; let cool.
Cut the pork roast into 3/4 inch slices. Arrange slices into an oven proof baking dish. A 9/13 Pyrex pan works good here.
Slather those pork steaks with the red chile paste. Use either a spatula or a basting brush to get the marinade evenly distributed.
Cover and chill 3 - 12 hours.
Preheat grill to 500 degrees, then lower to 350. Remove pork from marinade and grill pork steaks about 12 minutes per side. Grill pineapple and onion rings until caramelized, turning to cook on each side.
Transfer pork onions and pineapple to a cutting board and let rest 10 minutes, tented.
Stack three of the steaks on a cutting board, with the grain of the meat all running the same direction.
With a very sharp knife, slice the steaks very thin, across the grain. Tip from cooking school: A sharp serrated knife works well for slicing meat very thin. Chop the onions and pineapple.
Warm the corn tortillas. Place slices of pork on the tortillas and sprinkle on pieces of the grilled pineapple and onions. Add some chopped cilantro and serve with lime wedges. Some chopped avocado would work well here.