Roll out the ravioli paste as thinly as possible and cut into 2 in (5 cm) squares. Boil for a few seconds in salted water and drain.
Meanwhile put the smoked Ricotta into a covered ovenproof dish and warm for a few minutes in a moderate oven at 350°F (180°C) Gas 4.
Arrange half the ravioli squares on the bottom of four warmed soup plates. Place a ½tablespoonful of smoked Ricotta in the centre of each square and lay another pasta square on top. Grate black pepper over the pasta.
Heat the butter in a frying pan. As it heats, grate the nutmeg into it. As the butter browns take it off the heat. When the colour reaches a rich dark brown, pour in the lemon juice and spoon over the pasta.