Ingredients

1. 1 tablespoon unsalted butter
2. 2 shallots, finely chopped
3. 10 ounces firm white mushrooms, finely chopped
4. Salt and freshly ground white pepper
5. 3/4 pound chicken livers, well-trimmed and finely chopped
6. 1/2 cup finely chopped parsley
7. 2 cups heavy cream
8. 4 large eggs

Directions

1. Preheat the oven to 325°. Butter a 9-by-12-inch oval gratin dish that's about 2 inches deep. Melt the butter in a large skillet. Add the shallots and cook over low heat, stirring, until softened but not browned, about 4 minutes. Add the mushrooms and cook over moderate heat until they release their liquid and then absorb it again, about 8 minutes. Season with salt and white pepper and transfer to a bowl to cool.
2. Add the chicken livers and parsley to the mushrooms and season with salt and pepper. In another bowl, whisk the cream with the eggs and season with 3/4 teaspoon of salt and 1/4 teaspoon of pepper. Stir the custard into the chicken livers and pour into the prepared gratin dish. Bake for about 30 minutes, or until the custard is just set. Serve warm.
   

Make Ahead

The baked custard can be refrigerated overnight. Cover tightly with foil and rewarm in a 300° oven for about 25 minutes.