In a saucepan, boil about a litre and a half of water. Remove the steam, seeds and veins from the chillies and add to boiling water, turn off the flame and leave to simmer for ten minutes.
For the marinade, cut half of the onion into quarters and blend with the achiote, garlic, vinegar, orange juice, cloves, oregano, and the rehydrated chillies, add salt and pepper to taste.
Place the meat fillets in a bowl, add the marinade, and mix thoroughly to cover the meat well on both sides. Cover the bowl and let it sit in the fridge overnight.
Heat a little vegetable oil in a pan over medium heat, add the meat fillets and cook for 3 minutes f on each side or until brown. Make sure you gently scrape off the leftovers on the pan in between fillets to prevent burnt bits from sticking to the meat. .
Cut the pork into small pieces and put in a container with a lid, you can use the pan with a lid that fits.
Reheat the tortillas in a very hot pan, about 15 seconds on each side. I suggest you do them in piles of two to trap the moisture released by each tortilla.
Chop the other half of the onion along with the coriander and reserve for garnish.
Using a double tortilla for each taco, fill them with the pork, and add pineapple, chopped coriander and onion on top. Make sure you have some limes, cut in half, and salsa to the ready to put on each taco.
¡Buen provecho!