Chestnut and Whiskey Mousse with Chocolate and Walnut Biscuit and Chocolate Sauce

Name: Chestnut and Whiskey Mousse with Chocolate and Walnut Biscuit and Chocolate Sauce
Ingredients: 16 ounces chestnut puree; 1 cup whiskey (Recommended Maker's Mark); 3/4 cup cream; 5 gelatin leaves; 4 cups whipping cream; 20 egg yolks; 12 1/2 ounces sugar; 25 egg whites; 8 ounces sugar; 1.2 oz. cocoa powder; 4.5 oz. walnuts (chopped finely in a food processor); 2 cups water; 1 cup sugar; 1/2 cup whiskey; 1/4 cup sugar; 10 tablespoons cocoa powder; 4 ounces chocolate, chopped; 4 tablespoons honey; 1/2 cup bourbon; 1 teaspoon ground black pepper; 1/2 teaspoon espelette powder; 6 gelatin sheets; 7 ounces water; 12 3/4 ounces sugar; 5 1/4 ounces cocoa powder; 7 1/2 ounces cream