Prepare the onions and mushrooms by slicing them thinly. If your pork has bones, cut them away and then give the meat a pounding with the flat side of a tenderiser or rolling pin.
Flatten the pork until it is around 8ml thick.
Pour the flour in a bowl and season with salt and pepper before draining your pork through. Cook it in hot oil for a couple of minutes on each side until brown. Add the onions and mushrooms and let them cook down a bit.
Pour in the marsala wine and let it boil away until it has thickened up and the pork has cooked through.
Season with salt and pepper and pop on a garnish of chopped parsley.