Onion Marmalade, Gruyere and Sage Stuffed Flank Roll
You can ask the butcher to butterfly the flank steak for you.
Pre-heat the oven to 180°C/360°F.
Melt the butter in a large saucepan, add the red onions, brown sugar and mustard seeds and cook over a medium heat for about 15 minutes or until the onions are caramelised.
In the meantime, lay the flank steak on a chopping board with the grain of the meat running parallel to the front edge of the board.
Place your free hand flat against the top of the steak and using a very sharp knife, insert the knife along the trimmed edge of the steak. Keep the knife horizontal and slice lengthways through the middle of the flank, taking care to not cut all the way through the end seam of the meat.
Season both sides of the flank well with salt and freshly ground black pepper.
Finish off the marmalade by pouring both vinegars into the onion mixture and stirring continuously until most of the liquid has evaporated. Remove from the heat to cool and season to taste with salt and black pepper.
Evenly spread the onion marmalade, gruyere cheese and sage over the beef and tightly roll up the flank letting it rest seam-side down to keep it closed. Tightly tie about 6 pieces of butcher’s string around the flank roll to secure the stuffing.
Add a splash of olive oil to a large frying pan over a high heat and evenly brown the beef roll on all its sides. Sear the ends for only a few seconds to seal in the juices. It should be rare on the inside.
Wrap the flank roll in tinfoil and cook in the preheated oven for approximately 25 to 30 minutes for medium rare. Leave the meat to rest for 5 minutes before slicing it into thick rounds. Remember to remove the string before serving.
These rich, melt in your mouth beef medallions can be served with any side dishes of your choice. Crispy roast potatoes and a fresh salad would be delicious accompaniments to finish off this meal.