Chocolate and vanilla semifreddo

Method

1. Carefully line the base and sides of a 1 litre plastic container with a large piece of cling film. Set aside.

2. Crush the amoretti biscuits in a bowl and stir in a generous splash of liqueur. Spoon the mixture evenly over the base of the lined container and place in the freezer.

3. Break up the chocolate and place in a bowl, set over a pan of simmering water (taking care that the bottom of the bowl does not actually touch the water). Allow to melt. Once melted, remove from the heat and leave to cool a little.

4. Using an electric whisk, beat the egg yolks with the sugar until pale and thickened.

5. In a separate bowl, whisk the egg whites to form stiff peaks, then fold them into the yolks and sugar. Divide the mixture equally between two bowls. Add the melted chocolate to one bowl fold in until fully combined. To the other bowl, fold in the cream, another touch of liqueur and the vanilla seeds.

6. Remove the container from the freezer. Pour in the chocolate mixture first. Lightly tap the container on a work surface to level the mixture, then pour the vanilla mixture over the top. Tap gently again to even out. Cover with cling film and return to the freezer overnight to set (it needs to freeze for at least 12 hours). Any excess vanilla mixture can be frozen separately.

7. When ready to serve, allow to soften slightly at room temperature, then tip on to a chilled plate and cut into slices with a knife warmed in hot water. Serve slices on four individual side plates.