Cut the butter into pieces and chop the chocolate with a serrated knife.
Cut the passion fruits in half, empty them using a small spoon, and sieve* the flesh to obtain 1cup (250ml) of juice. Bring it to a boil. Melt half the chopped chocolate in a bain-marie*. Pour the hot juice onto the chocolate in three batches.
Once the temperature of the mixture reaches 140°F (60°C), incorporate the butter, little by little. Mix until the ganache is smooth. Pour into a gratin dish. Lay a sheet of plastic over it, touching the surface of the ganache. Keep it in the refrigerator until it becomes creamy.
Passion Fruit Macaron
Sieve* the confectioners sugar and the ground almonds. Mix the colorings into half of the egg whites. Work them into the sugar almond mixture. Boil the water and superfine sugar to 245°F (118°C). As soon as the syrup reaches 240°F (115°C), start to beat the second half of the egg whites to form stiff peaks.
Pour the sugar solution at 245°F (118°C) onto the beaten egg whites. Whisk and allow to cool to 120°F (50°C).
Work this meringue into the sugar almond mixture, and mix it all together, allowing it to settle. Pour it into a pastry bag fitted with a No. 11 nozzle.
Pipe circles of the paste, approximately 1½-inch (3.5-cm) in diameter, spacing them 1-inch (2-cm) apart on a tray lined with parchment paper or on a Silpat mat*. Tap the tray on the work surface, covered with a tea-towel.
Using a sieve, sprinkle the shells with a dusting of cocoa powder. Leave them to form a crust, for at least 30 minutes, at room temperature.
Preheat a convection oven to 350°F (180°C). Place the tray in the oven and bake for 12 minutes, opening and closing the oven door quickly twice during baking. Take them out of the oven, slide the shells onto the work surface and leave to cool.
Pour the ganache into a pastry bag fitted with a No. 11 nozzle. Pipe it generously on to half of the shells. Cover them with the other shells. Take them out of the refrigerator 2 hours before serving.