Boil the chiles 3 to 5 minutes in two cups of water. Reserve. Once the chiles cooled off, mix all adobo ingredients in a blender into a uniform thick sauce. You may use the water where you boiled the chiles to help the blender. Marinate the meat with the adobo for at least a couple of hours in the refrigerator.
Set up your wood or charcoal or gas grill to low heat and grill the marinated pork fillets and the whole pineapple slices. Heat the tortillas. Chop the cooked meat and pineapple and make yourself some tacos. Garnish with fresh onion and cilantro, and with your favorite salsa.
