Lay the flank steak on a chopping board with the grain of the meat running parallel to the right 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.
Evenly spread the basil pesto and garlic over the inside of the butterflied beef.
Place the mozzarella slices over the meat in rows and top with sundried tomatoes, parsley, 2/3 of the pine nuts and chilli flakes 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 the linguine to a saucepan of boiling water and cook according to the packet instructions or until al dente. Drain and set aside for serving.
Add a splash of olive oil to a large frying pan and cook the stuffed flank roll over a medium-high heat for 4 to 5 minutes on each side, evenly browning the beef and cooking for a total of around 20 minutes.
Leave the meat to rest for 10 minutes before slicing it into thick rounds and remember to remove the string before serving.
Drizzle olive oil over the cooked linguine, generously sprinkle with grated parmesan cheese and place beef medallions over the top. Garnish with basil and remaining pine nuts. Bon appetit!