Leave the bacon in a saucepan and fry until crispy. Remove from the fat and set aside. Lightly fry the meat in the omitted fat. Then add the ketchup and a little water (the sauce must not be too thick, otherwise it will burn). Let everything stew over a mild heat for about 1 hour 10 minutes, then add the onions and stew until they are still firm to the bite. Season to taste with the spices and stir in the bacon just before serving.