Remove the veins from the foie gras. Mix together the salt, sugar, pepper and four-spice powder. Season and drizzle the Pommeau over both sides of the foie gras. Re-assemble the lobe of foie gras, roll it in cling film and leave to rest in the refrigerator for 1 hour.
Remove the cling film, place the foie gras onto a clean tea towel, tightly roll the foie gras into a cylinder, tie together both ends of the towel. Plunge the towel-wrapped foie gras into a pot of boiling salted water and turn off the heat under the pan. Leave for 8 minutes. Remove the foie gras, unroll the towel, and then re-wrap it.
Set aside and chill for 12 hours. Serve 2 slices per person accompanied by an apple compote.
Enjoy the foie gras with a glass of well-chilled Pommeau de Normandie.