Can the syrup and custard for the Raspberry And Lemongrass Trifle be made in advance? A day before assembly? I will be making this in a friend's house and would like to do as much prep at home first as possible.
Nigella's Raspberry And Lemongrass Trifle (from NIGELLA BITES) can be mostly made a day ahead and if anything can be slightly better as an overnight rest in the fridge helps the sponges to soften and the flavours to mingle together. If you are using your own bowl for the trifle then you could assemble the sponge, raspberry and custard layers (to the end of step 3 in the method) and then refrigerate this part-made trifle overnight, before taking to the venue the next day. The whipped cream topping and caramel sauce can be made and added just before you want to serve the trifle.
However as the custard contains eggs the trifle should be kept cold while it is being transported and should not be left at room temperature for more than 2 hours. If this is difficult to do, or you need to take the elements of the trifle separately, then you can make the syrup and custard in advance, though the trifle will not be quite the same as if the custard is poured over while it is hot. The syrup can be stored in an airtight conatiner in a cool place overnight. Once the custard has been made then you should transfer it to a bowl or an airtight container, press a piece of baking parchment (parchment paper) or clingfilm (plastic wrap) on the surface of the custard, to prevent a skin from forming, cover and refrigerate. You will find that the pre-made custard doesn't work its way as well into any cracks between the sponges of the trifle as it will be less liquid when cooled. Also spread the whipped cream over the top carefully as the pre-made custard won't have formed a firm surface on the trifle for the cream to sit on.