Cut the bacon first into slices and then into strips. Clean, wash and cut the leek into rings. Drain kidney beans, rinse with cold water and drain. Leave the bacon strips in a pot without fat until crispy. Add the leek and fry briefly. Add kidney beans and baked beans to the bacon mixture and heat.
Pour about 1/2 litre of water into the stew while stirring, bring to the boil and stir in the stock. Cover the bean stew and simmer at low heat for about 10 minutes. Season to taste with ketchup, sugar, salt and cayenne pepper. Parsley, wash, dab dry and chop finely. Sprinkle over the stew before serving