Heat the oil or lard in a pot and over high heat fry the pork in batches until nicely browned. Remove a spoonful of fat with a spoon and then add the onion to the pork and fry over reduced heat until onion starts to soften. Add half the wine, cumin, garlic and salt and pepper. Stir through, cover and simmer for about 25 minutes or until the pork is tender. Add the rest of the wine and the lemon pieces and boil over high heat, stirring until sauce thickens. Reduce the heat, stir in the coriander and adjust seasoning to taste. Cover and remove from heat for five minutes before serving. If you want to make the stew in advance and it needs to stand for longer only add the coriander shortly before serving.