For the beef lung roast, season the piece of meat with salt and pepper and coat it thickly with mustard. Heat the oil, brown the lung roast on all sides and place in a hot oven (160 °C). Baste with shortening from time to time.
After 30 minutes, remove the meat from the tube and keep warm with the lid closed. After about 10 minutes, cut the beef lung roast into slices and bring to the table with various vegetables.