Line the base of a baking dish with matzoh or water biscuits.

Add all the custard ingredients to a saucepan, whisk to combine until there are no lumps. Turn on the heat and slowly bring to the boil, stirring continuously. 

Once the custard thickens and it becomes harder to whisk the mixture, pour it over the biscuit layer. Set to one side to cool, then transfer the dish to the refrigerator. 

Meanwhile, place all the berry layer ingredients in a blender and blitz on high until thoroughly mixed. For a smoother texture, strain the blended mixture through as sieve – although this is optional. 

Pour the berry mixture over the cooled custard layer, and return the dish to the fridge.

To make the meringue layer, first preheat the oven to 130 Celsius. 

Take a large mixing bowl, and ensure it is completely clean – there must be no traces of grease or the meringue mix won’t work. Add the vinegar and aqua faba and beat until stiff – you should be able to hold the dish upside down above your head for a few seconds without any of the mixture falling on your head. 

In a separate bowl, mix together the caster sugar and cornflour. Add the sugar mixture a tablespoon at a time, waiting 20 seconds between each sugar addition. 

Dollop spoonfuls of the meringue mixture on top of the berry layer – try to form lots of peaks which will go golden and crisp when grilled.

Place the dish into the preheated oven and bake for 15 minutes. Then, turn on the grill to grill the meringue for 3 minutes – watching carefully throughout to prevent the meringue browning too much.

Remove the dish from the oven and serve immediately!