For the foie gras royale, devein and mix the foie gras with the cream, eggs and salt in a blender, pour into verrines and cook in a bain-marie in an oven at 90° for 20 to 25 minutes. Let cool.
For the lentil cream, in a large saucepan put the lentils and 3 times their volume in cold water, the peeled onion and bouquet garni. Bring to a boil and cook for 25 minutes.
Drain the lentils, add the broth and cream and blend. Strain to remove small skins.
Pour the cream on the royal.
Toast the bread and cut it into small cubes of a little less than a centimetre.
Place bread cubes on top of the cream.