Start by finely chopping the parsley and oregano, then mix them together with the olive oil to make the marinade, adding salt and pepper to taste.
Skin the monkfish tails, being very careful to remove all of the membrane, or the fish will take on a rubbery texture when cooked. Place the monkfish in a bowl and cover with the marinade, leave for 20 minutes.
Arrange 4 slices of the speck (or parma ham) side by side on a work surface and place 3 of the sage leaves along the centre. Place one of the marinated fillets on the ham, and roll up the sides to enclose the fish. Repeat with the other fillet and the rest of the ham, and place on a baking tray. Cook in an oven at 200C/400F/Gas6 for 12-15 minutes.
For the sauce, finely chop the shallot and fry in a little oil until soft. Add the vinegar and boil until almost dry, then add the red wine and reduce to about one quarter. Add the stock and reduce by about half. Strain through a sieve and season to taste.
To serve, slice the cooked fillet, arrange the slices on the plate and drizzle with the sauce.