Take the foie gras out of the refrigerator and let it sit for 1 to 3 hours (depending on room temperature) until it is soft.
Remove from packaging, and separate the lobes.
Remove any of the larger veins from the big lobe of foie gras (1), using a small pointed knife to incise about 1/4 inch deep in an “upside down Y” pattern, starting where the lobes were connected, and following the path of the veins. It should resemble figure (2).
Sprinkle generously with sea salt and white pepper. And add a splash of Armagnac, Cognac, Brandy or Sauternes (approx 3 tsp per lb).
Place the foie gras into a terrine, pressing it into the shape of the terrine with your fingers (3) to make the fit as tight as possible (4).
Cover with plastic wrap, and marinate in the refrigerator overnight (5).
The next day, take the terrine out of refrigerator for 1 hour before cooking, and preheat the oven to 200ºF.
Cook the foie gras in the oven in a bain marie (place the terrine in a Pyrex or baking dish and fill halfway with room temperature water) for about 30 minutes per pound.
Cooking is complete when you see a thin layer of melted yellow foie gras butter on the surface.
Remove the terrine from the oven and from the bain marie and uncover. After 30 minutes, drain off excess foie gras butter, reserving it for later use in sautéing potatoes or other vegetables.
Optional: Lightly press the foie gras as it cools by covering it with a piece of stiff cardboard cut slightly smaller than the terrine and wrapped in several layers of plastic wrap. On top of the cardboard, place a bottle of wine or two one-pound cans, and let the terrine cool for another 30 minutes. Then take off the cardboard and the weight, and remove the excess foie gras butter (6). We recommend you freeze this butter for future use.
Cover tightly and place in refrigerator for 2 to 3 days to allow the flavors to fully develop.
Serve cold, spread over toasted bread.
Freezes well up to 6 months.