Hubert Keller's Chocolate Mousse Burgers
3 cups Chocolate Mousse
Passion Fruit Gelée:
1 cup (8 ounces) unsweetened passion fruit concentrate
4 teaspoons powdered gelatin
About 5 tablespoons sugar
4 glazed doughnuts without central holes or beignets
1 pint basket ripe strawberries
1 tablespoons plus 1teaspoon sugar
1/2 cup heavy cream
1 large kiwi, peeled and very thinly sliced
4 fresh mint sprigs
Line a small baking dish with plastic wrap and spoon Chocolate Mousse into dish; freeze until firm, about 1 hour. Using a 3-inch round cookie cutter (or whatever size fits your doughnut bun), cut out Chocolate Mousse rounds for the burger. To make the gelée: in a small, nonreactive saucepan stir together the passion fruit concentrate and sugar. Add the sugar by tablespoonfuls until the sweet/tart balance reaches your preference. The amount needed will vary by brand. Whisk in the gelatin until well mixed and set aside to soften for 2 minutes. Prepare an ice water bath by emptying a tray of ice cubes into a pan of cold water. Line a 9- by 12-inch baking pan or baking sheet with plastic wrap. Place the saucepan with the passion fruit mixture over low heat and whisk gently to prevent sticking and scorching while the mixture comes to a boil, about 4 minutes. Move the saucepan off the heat and hold it in the ice water bath. Whisk until the mixture has cooled to about room temperature. Skim off any remaining foam with a shallow spoon. Pour the gelée onto the prepared baking pan and tilt and smooth the mixture into an even layer. Refrigerate until set, about 1 hour. Make sure the pan sits evenly so the gelée forms a layer of even thickness. Gelée keeps, covered and refrigerated, 4 days.
To assemble the burgers: sort through the berries to choose 4 of the largest and cut these into very thin lengthwise slices. Puree remaining berries in a food processor with about 1 tablespoons sugar (more or less to taste, depending on the sweetness of the berries). In a small bowl, beat the cream with the remaining 1 teaspoon sugar (more or less to taste) until it forms soft mounds. Cut the doughnuts in half horizontally. While the gelée remains in the pan, trim the edges with a small sharp knife so they are straight. Carefully lift the gelée out of the pan onto a work surface. Then cut the gelée into 3-inch squares, cutting through the plastic wrap as well. Run your knife under water frequently so it cuts cleanly. Place the bottom half of each doughnut on a dessert plate. Add a dollop of whipped cream and then a chocolate burger. Arrange a sliced berry, points outward, on top of the burger, and then add a circle of overlapping slices of kiwi. With the tip of a small knife, pry up a corner of a square of gelée with its plastic wrap and place it, plastic wrap up, on the kiwi. Peel off the plastic wrap. Top with the remaining bun halves and tuck a few fresh mint leaves under the top bun. If necessary, secure the top bun with toothpicks. Spoon a little strawberry sauce around the burger and serve immediately.