Put the chicken in the pan, then pour in 300ml cold water. Bring to the boil, then reduce down to a simmer and cook for 20 mins, turning once, until the chicken is cooked through. Remove chicken from water (saving the liquid) and when it’s cool enough to handle, shred with your fingers or a fork.
Halve the chillies, pull out the seeds and discard. Place in a small bowl and cover with boiling water. Leave to soak for 20 mins until softened, then discard the water, roughly chop the chillies then put into a blender.
Heat a frying pan and tip in the tomato. Cook for 5 mins, until the tomato skins start to blister and turn brown. Add to the blender. Heat the oil or lard in the same frying pan and cook the onion, garlic and almonds for 5 mins. Stir in the raisins, oregano, cumin and cinnamon, then cook 2 mins more until the onion is softened, the almonds are golden and the raisins have puffed up. Tip into the blender with 100ml of the chicken poaching liquid and give it a good whizz.
Pour the mixture back into the pan, stir in 350ml of the poaching liquid and chocolate and let it simmer for 20 mins. To serve, soften the tortillas in a microwave for 30 secs then pile the chicken on top, spoon over the sauce and roll up. Serve scattered with coriander leaves, limes and more chopped almonds.