Sixpenny's chocolate-marsala mousse with vanilla ice-cream

Combine yolks, sugar and marsala in a large heatproof bowl set over a large saucepan of barely simmering water (don't let the bowl touch the water). Whisk until thickened and mixture reaches 73ºC on a cooking thermometer (4-5 minutes). Remove from heat, stir in chocolate until melted.

Combine cream and gellan gum powder in a saucepan; mix well. Heat over medium heat just until boiling, then simmer for 30 seconds to activate the gellan gum.

Pour cream mixture into yolk mixture, whisking constantly. Working quickly, pour mixture into a deep tray or slice pan to cool to room temperature and set (30 minutes).

Meanwhile, to make Swiss meringue, combine eggwhites and sugar in a heatproof bowl set over a large saucepan of barely simmering water (don't let the bowl touch the water). Stir until sugar is dissolved and mixture reaches 68°C (6-7 minutes). Transfer to a stand mixer and whisk until thick, glossy and completely cooled.

Transfer set chocolate mixture to a blender and blend until smooth; transfer to a bowl. Gently fold in Swiss meringue in two batches until just combined. Spoon into serving dishes and refrigerate until chilled and set (3-4 hours). You can also pipe the chilled mixture using a 1.5cm star nozzle. Serve with vanilla bean ice-cream.