Marinated pork is the key to classic Mexican tacos al pastor. With this in mind, the recipe is split into two sections: the marinade and putting the tacos together.
Preparing the marinade:
Chillies are the basis of the marinade for tacos al pastor, so the first thing to do is to soak the ancho chile pepper and the guajillo chilli for 30 minutes in very hot water until soft. Before soaking, remove the stem and the seeds. After 30 minutes, drain the chillies and put the water to one side.
Cook the chillies and the onion in boiling water for five minutes.
Remove the chillies from the boiling water, drain them and put them in a blender with the vinegar, chipotle chilli, achiote paste, cumin, garlic, oregano, clove, orange juice, salt, pepper and laurel leaf.
Blend all the ingredients together until they form an even mixture. If the mixture is very thick, add a little of the water the chillies were soaked in.
Put some of the marinade in the bottom of a serving dish and then add the salted meat. It is important to make sure all the pieces of meat are covered.
Cover the dish and leave it to marinate for three or four hours in the fridge so that the meat can absorb the flavours. In Mexico the meat is usually marinated overnight. If you have time, let the meat marinate for 24 hours.