1) Rub the meat with the seasoning, salt, black pepper, cayenne, paprika and chilli flakes, cover and refrigerate for 2 to 3 hours.
2) Preheat the oven to 140C/Gas 1.
3) Place the meat into a roasting pan with the bacon fat, add the onions and garlic, and then saute for 15 minutes. Deglaze the pan with the wine then add the Worcestershire sauce, beef stock and bay leaves.
4) Place the roasting tray in the oven and cook for 3 hours, uncovered, or until an instant-read thermometer inserted into the meat registers 57C in the centre. Remove, allow to cool, then slice very thinly.
5) Cool the stock in the roasting pan and remove the fat that rises to the top. Strain and then reheat the liquid and add to the sliced meat.
6) Place some meat on each toasted roll, ladle over some of the stock and top with the giardiniera vegetables and red peppers.