Preheat the oven to 150°C. Spread a bed of coarse salt in a large oven dish, place the potatoes on top, and bake for 30 minutes until tender.
As a chef with years of experience in French cuisine, I recommend slicing the foie gras into escalopes no thicker than 1 cm. Quickly sear them in a dry hot pan, pat dry with paper towels, and set aside to rest.
Peel and finely chop the shallots. Mince the chives, parsley, and chervil.
Peel the warm potatoes and mash them lightly with a fork for a rustic texture.
In a saucepan, melt the butter over medium heat. Sweat the shallots until translucent without browning. Stir in the mashed potatoes, fresh herbs, salt, and pepper. Mix gently over low heat for a minute to infuse flavors.
Butter a 30 cm springform pan and line it with buttered parchment paper. Spread half the potato mixture evenly in the base.
Layer the foie gras escalopes over the potatoes, then top with the remaining potato mixture. Smooth the surface with a spatula, sprinkle with breadcrumbs, and bake for 10 minutes until golden.
Serve hot or warm, accompanied by a fresh green salad of lamb's lettuce or mesclun for a perfect contrast.
