Remove the foie gras from the refrigerator 1 hour before working with it and bring it to room temperature so that it softens. Preheat the oven to 160 °C. Prepare the seasoning of foie gras salt, pepper and possibly Espelette pepper or any other spices according to your tastes.
Separate the two lobes of the liver by opening it in two with your fingers in the direction of the length of the liver. For the large lobe, remove the Y-shaped main vein from the base of the liver and finish with the second vein under the first. Use a small spoon to lift and remove the vein without breaking it. For the under-lobe, the 2 veins are also one above the other, but in the form of an X. Progress in the same way as for the first lobe.
To season the liver lobes, use 16g of seasoning per kilo, or about 8 g per lobe. Use fleur de sel (or sea salt flakes) and allow the seasoning to soak the liver by basting it with cognac. Marinate longer or shorter depending on the desired strength. Ideally leave it to rest for ½ day.