Dark chocolate torte with mint ice milk

Preheat the oven to 180°C, gas mark 4. Grease and line a 20cm round cake tin (not loose-bottomed or springform) with baking parchment. Combine the chocolate and butter in a large heatproof bowl and set over a pan of barely simmering water (ensure the bowl is not touching the water). Allow to melt, stirring occasionally, then remove from the heat and set aside to cool a little.

Meanwhile, whisk together 4 eggs, 250g of sugar and ½ teaspoon of salt in a freestanding mixer (or using an electric hand mixer) on medium speed until pale and very airy (8-10 minutes). Gently fold in ⅓ of the cooled chocolate, along with the coffee, followed by the remaining chocolate. Sift in the cocoa powder and gently fold together until no clumps remain.

Bring a kettle of water to the boil. Pour the batter into the prepared tin and level the top. Put the tin in a large roasting tin and pour enough boiling water around it to meet the depth of the batter; bake for 35-45 minutes until there is just a slight wobble in the middle. Carefully remove the cake tin from the water and cool in the tin overnight.

Meanwhile, make the ice milk. In a high-speed blender, whizz the mint leaves, milk and xanthan gum until smooth, then pass through a fine sieve into a large bowl and set aside. In a freestanding mixer (or using an electric hand mixer), whisk the egg white and ¼ teaspoon of salt until pale. Gradually add the remaining sugar, whisking constantly, until soft peaks form.

Fold the egg whites into the milk mixture until roughly mixed through. Churn in an ice-cream maker according to appliance instructions, then transfer to an airtight container and freeze for at least 2 hours. If you do not have an ice-cream maker, pour the mixture into a freezerproof container and freeze for 6 hours, stirring every hour. Once frozen, whizz the ice milk in a food processor until smooth, then freeze again for another 2 hours.

To serve, remove the cake from the tin, turning it out onto a serving plate so the crust is on the bottom. Slice and serve alongside a scoop of the mint ice milk.