Heat half of the margarine in a frying pan and cook the diced onions.
Season the meat slices with salt and pepper and brush them with mustard. Cover them with sausage meat and onion fondue. Roll them up and tie them like paupiettes.
Heat the rest of the margarine in the frying pan and brown the paupiettes on all sides. Reserve them.
Replace the meat with carrots and diced tomatoes. Add the wine and reduce.
Return the maupiettes and let simmer for 1 hour on low heat.
Serve the paupiettes topped with the cooking juices
Serve with Provencal tomatoes or Swiss chard gratin.