1) Preheat the oven to 120C/Gas 1.
2) In a Dutch oven, sweat the onions, garlic, chillies, coriander, annato seed paste, chilli powder, cinnamon, oregano and cumin in the olive oil. Add the lamb stew meat, and continue to cook until the meat has caramelised just slightly. Deglaze with the beer.
3) Add the lamb stock and tomatoes. Put the lid on the pan and pop it into the oven while the shearing goes on. Stir it occasionally and cook for about 4-6 hours.
3) When the shearing is done, grate the chocolate into the chilli, which by now should be sublime. Ladle into bowls, top with the grated Cotija cheese and serve with a nice cold beer, fresh cornbread, a salad and feel the flavours of Mexico transport you!