Take 1 each of dried chiptole, Guajillo, Pasilla and New Mexico chillies. Cover with boiling water and leave 25 minutes. Drain, reserving the water, and crush in a mortar and pestle along with 1 tbsp salt, 1 tbsp pepper, 1 tbsp toasted cumin and coriander seeds, 1/2 tbsp toasted caraway seeds, four cloves garlic, the juice of one lime, and a splash of olive oil. Coat a goat leg with the paste, cover and refrigerate overnight.
Place goat leg in a roasting pan, roast 20 minutes at 250C. Meanwhile, mix 1 tin crushed tomatos, 1 thinly sliced onion, 1 minced garlic clove, 1 tbsp each coriander, cumin and chipotle powder, juice of one lime, 1/4 cup brown sugar, 1/4 cup malt vinegar, and the reserved chilli water. Add to pan, reduce oven heat to 160C, tightly cover pan with foil and roast five hours.
Remove meat from pan and place in warm oven. Pour sauce into a saucepan, puree with stick blender, and simmer until reduced by half.
When meat has rested, shred with two forks. Stir in sauce, and add salt and pepper to taste.
Serve on fresh corn tortillas with red cabbage, carrot, charred corn, lime and coriander slaw and pickled red onion.