Preheat the oven to 160 °C.
In a blender, whiz the eggs, the egg yolks, the cream, the milk and the uncooked goie gras. Add salt and pepper to your taste. Then pour the mixture into buttered dariole molds. Put them in a bain-marie (an ovenproof dish filled with haot water) and put it in the oven for 30 minutes.
Shell the white beans. Peel and chop the onion.
Sweat the onion for 2 minutes in a casserole dish with a knob of butter and a pinch of salt, then add the beans. Cover with water and cook on a low heat for 20 minutes.
Once the beans are cooked, add the cream and bring to a boil. Whiz and check the seasonning and add some water if necessary to get a creamy consistency.
Roughly chop the hazelnuts and pick the chervil leaves.
In soup plates, turn out the foie gras royales, then add the white bean cream. Sprinkle the royales with chervil and hazelnuts. Then decorate them with the balsamic vinegar reduction.
«If you're using dry white beans, steep them for two hours in water before using them.»