Slice the onions and tomatoes. Finely chop the garlic, and pick the coriander leaves, finely chopping the stalks. Slice the chicken into strips.
Heat the oil in a pan over medium heat and when hot, sauté the onions, garlic, coriander stalks, spices, and flaked chilli for 5 minutes until the onion is soft but not coloured.
Add the chicken strips and cook for a couple of minutes, then add the tomatoes and ¼ cup of water. Bring to a boil, then reduce heat and simmer, partly covered, for 35 to 40 minutes, or until the chicken breaks apart when pressed with the back of a spoon. Add a splash of water if it looks too dry at any stage.
For the salsa, break up the pepper and place under a hot grill or hold it with tongs over a gas flame. Once blackened all over, place in a bowl, and set aside to cool.
Chop the tomatoes, put them in a colander with a pinch of sea salt and place it in the sink for 15 minutes to allow the salt to draw out some of the tomatoes’ water, and then give the colander a good shake.
Peel the skins from the pepper and discard along with the seeds, then place them on a board with the onions and chop.
Place black beans to boil then strain excess water.
Add the tomatoes and pick over the coriander leaves and continue chopping until you have a fine salsa. Transfer to a bowl, and season with black pepper and a good squeeze of lime juice.
Shred the chicken using two forks, then drain and stir the black beans into the chilli. Continue cooking for a couple of minutes then remove from heat, and then stir in the coriander leaves.
Chop the lettuce, then serve the chilli in the tortillas with the lettuce, a spoonful of salsa and a drizzle of yoghurt, with lime wedges on the side.
