A photo essay at The Guardian gives advice on how to make a ‘Shooter’s Sandwich’. It involves packing the ingredients into a loaf of crusty bread, wrapping it in butcher’s paper, and pressing it overnight under weights:
(” You’ll need your choice of crusty loaf, a couple of good steaks – these are rib-eyes – roughly the same shape in plan as the loaf, 500g of mushrooms and 200g of shallots”) and the final product (” Serve sliced like cake accompanied by something vaguely vegetable-based to assuage the guilt.”
Apparently, the name comes from Edwardian times, when it was created as a snack that the cook could prepare the night before and was essentially a portable beef Wellington for the fox-hunting gentleman.
How to Make a Shooter’s Sandwich [The Guardian]