Dark and White Chocolate and Strawberry Swiss Roll with White Chocolate Custard

Preheat the oven to 180ºC (about 355ºF). Grease and line a 40cm by 28cm Swiss roll tin.

In a large bowl, beat the eggs and caster sugar until they are light and fluffy and three times the original volume. Add the warm water. Sift in 1/3 of the flour and gently fold in. Repeat until all the flour has been added. Pour into the tin, level the top with a spatula and bake for 12-15 minutes, until just coming away from the edges of the tin and springy to touch.

Lay a piece of baking paper (bigger than the cake) on a worktop and sprinkle it evenly with caster sugar. Turn the Swiss roll out onto the baking paper gently and leave to cool for a few minutes. Peel away the baking paper it was baked in and cover with a slightly damp, clean tea towel (to prevent it from cracking as it dries).

Make the filling. Melt the dark chocolate and 100ml of the double cream in a saucepan over a low heat. Allow to cool and then put it in the fridge to cool for a few minutes. Technically you should let it cool to room temperature before putting it in the fridge but I do not have the patience for this. Remove from the fridge and leave on the side until ready to use.

Meanwhile, in a bowl, whip the remaining 200ml of double cream until soft peaks form.

When the cake has cooled, remove the towel and spread the cake with the dark chocolate, then the cream and then sprinkle over the strawberries evenly. Using the baking paper to help you, gently roll the short side of the cake inwards. You want to roll it gently enough that it doesn’t squidge out all the filling, but tight enough that it looks neat.

Melt the 100g white chocolate in a bowl set over a pan of simmering water, stirring occasionally. When it is smooth, drizzle it over the Swiss roll.

Make the custard. Break the 75g white chocolate up into pieces and add to any leftover melted white chocolate (from above).

Heat the milk in a saucepan until fairly hot but not boiling. You should be able to dip your finger in it without crying like a girl. If you have a thermometer, it should reach about 60ºC (140ºF). Remove from the heat.

In a bowl, mix together the egg yolks and sugar, beating well. Pour in the hot milk and stir well, then return the mixture to the hot pan and cook over a low heat until the mixture is thick enough to coat the back of a wooden spoon.

Pour the mixture into the bowl of white chocolate. Allow to stand for a minute, then stir well until the white chocolate has melted and the custard is smooth. Serve as soon as you like, which I assume is immediately.