Heat the lard in a lidded frying pan, add the onion and fry for five minutes, or until softened. Remove the pan from the heat and stir in the paprika, adding more or less to taste. Add the pork and a splash of water. Simmer over a low heat for about 5 minutes.
Add enough boiled water to cover the meat, bring back to the boil and add the tomato purée, green pepper and tomatoes. Season with salt and freshly ground black pepper. Cover with a lid and simmer for 1 hour or until the pork is tender.
To thicken the sauce, mix the cornflour and two tablespoons of cold water to form a paste, then stir into the stew. Bring to the boil again to thicken. Check the seasoning, and season with salt and freshly ground black pepper to taste.
Serve the stew with creamy mashed potato, or macaroni. The dish also goes well with finely sliced cucumber which can be lightly pickled with a splash of white wine vinegar and a sprinkling of caster sugar.