Stir 1 tbsp of the leftover gravy into the mayonnaise; set aside. Spread 4 slices of the sourdough with a thin layer of the mayo. Lay 2 slices mayo-side down then spread with the cranberry sauce and top with the turkey or beef and thinly sliced Brie. Sandwich with the remaining bread, mayo-side up.

Heat a non-stick frying pan over a medium-low heat and toast for 2-3 mins each side, pressing down with a spatula, so the cheese melts and the bread becomes golden. Meanwhile, toast the last 2 slices of bread and spread with the remaining gravy mayo.

Reheat the remaining leftover gravy in the microwave until piping hot. Remove the toasted sandwiches from the pan and top with the shredded sprouts, pickled red cabbage and crisps. Press the toasted bread on top, mayo-side down, then slice in half and serve with the hot gravy on the side for dipping.