Stand mixer or electric whisk (not essential, but highly recommended)
Piping bag (optional)
Ingredients
For the pastry
180gplain flour
1tbspcaster sugar
60mlneutral oil
For the filling (see notes)
80gcashewssoaked in boiling water for 15mins
Pinchof ground turmeric
2tspcornflour
4tbspcaster sugar
120mlfresh lemon juice
2lemonszest only
For the meringue
120mlaquafabachickpea water
125gcaster sugar
½tspwhite wine vinegar
Instructions
To make the pastry combine flour and sugar in a large bowl. Add the oil and rub it into the dry ingredients with your hands. Finally, add water gradually until a rough dough forms. You should be able to pinch a piece of dough and it should hold its shape. Wrap it in a piece of cling film and chill in the fridge for 30 mins.
Once chilled, roll out the pastry between two sheets of baking paper until you get a rough circle around 2 mm in thickness (this makes the dough easier to work with). Place the rolled-out dough over the tart tin and trim any excess pastry and crimp if desired. Dock the pastry by pricking the pastry over the bottom with a fork. Chill for 30mins and preheat the oven to 175C /Gas 4.
While the pastry is chilling, prepare the filling (see notes for raspberry filling instructions). Rinse the soaked cashews and place in a blender with the lemon juice and sugar. Blitz several times until you get a completely smooth liquid.
Pour cashew and lemon mixture into a small saucepan and add the lemon zest. Warm the mixture gently stirring constantly so it doesn’t burn. Taste the mixture and add more sugar if necessary. Mix the cornflour with 1 tbsp of water in a small bowl and add this to the warm lemon curd. Gently bring the mixture to the boil (stirring the whole time) and allow it to bubble for two minutes to let it thicken (the mixture will thicken further as it cools).
Finally, add a pinch of salt and a pinch of ground turmeric to give the curd a pale yellow colour, this can be overpowering so add a tiny pinch.
Line the pastry shell with baking paper and fill with baking beans. Blind bake the pastry for 20 mins, then remove the beans and bake for another 15 mins. Cool pastry down completely before filling.
Make the meringue just before assembling the pie. In a large, clean bowl (make sure there is no greasy residue, it is best to use a glass or metal bowl for this) beat aquafaba and vinegar with an electric whisk or use a stand mixer until you get stiff peaks. To test if whipped aquafaba is ready, gently turn the bowl upside down. If the mixture does not start sliding down, you can start adding sugar. Otherwise, keep on whipping until the mixture stays in the bowl when inverted. Add the sugar a tablespoon at a time, whipping well after each addition. The mixture should be sticky and glossy when the sugar has been incorporated.
To assemble, fill the pastry with your chosen filling. Pipe meringue on top using a piping bag (again needs to be completely grease-free), alternatively spoon on the meringue and shape into swirls. Toast the meringue under a hot oven grill for a few minutes watching closely as it can burn very quickly. The pie may also need rotating after a minute to brown evenly. Alternatively, you can use a blow torch.
Let meringue pies stand for at least an hour after toasting the meringue so that it stabilises.
Notes
To substitute the lemon filling for raspberry, you’ll need 400g raspberries, zest and juice of one lime, and 1 tbsp cornflour.Combine the raspberries, sugar, and lime juice in a small saucepan and bring to a simmer and leave to bubble for 5 minutes. Meanwhile, combine the cornflour and 1 tbsp of water in a small bowl and add this to the raspberries. Gently bring the mixture to the boil (stirring the whole time) and allow it to bubble for two minutes to let it thicken (the mixture will thicken further as it cools). Finally, add the lime zest and a pinch of salt.