Tilly's trifle

First, make the jelly. Soak the gelatine leaves in cold water until floppy, then drain. Strain off the juice from the cherries into a jug – you should have around 350-400ml. Put the juice and the redcurrant jelly in a pan, stirring until it boils and the redcurrant jelly has melted. Take off the heat, cool for a few mins, then stir in the gelatine until it dissolves. Pour into a shallow pan or dish to cool, then chill until set.

For the custard, scrape the vanilla seeds from the pod into a large bowl. Add the egg yolks, 40g sugar and the flour, then whisk until pale and creamy. Pour the cream into a medium-size pan and bring just to the boil. Gradually whisk the cream into the yolk mix. Wipe out the pan, then return the mixture to it. Cook slowly over a low heat, stirring with a wooden spoon until thickened – take extra care to stir well at the edges of the pan. Cool, stirring every so often.

To assemble the trifle, slice the Swiss roll into 8 pieces and arrange on the base and around the inside of a large glass serving bowl. Sprinkle with the sherry, if using.

Turn the jelly out onto a board and chop with a sharp knife. Scatter the drained cherries and chopped jelly on top of the Swiss roll, then sprinkle over the crushed amaretti.

Pour the cooled custard over the biscuits, then return to the fridge until cold (about 2 hrs). For the topping, whip the cream to soft peaks with 1 tbsp sugar, then spoon or pipe it over the custard. The trifle can be covered and chilled for up to 2 days at this point.

To serve, sprinkle over the pistachios and remaining amaretti. Push back the leaves of the physalis and poke the fruit into the cream.