Place the biscuits into a food processor and pulse until they are broken down. Combine with the melted vegan butter in a mixing bowl, then press the mixture into the bottom and sides of an 8in pie tin. Place the pie base into the fridge for at least 30 minutes while you prepare the filling.
For the lemon curd filling, add the butter, lemon juice, coconut milk, vanilla essence, and icing sugar to a medium-sized saucepan over low heat. Bring to a simmer whilst stirring regularly.
In a small bowl, whisk the cornflour and agar agar powder with 3 tbsp of plant milk until dissolved. Pour the mix into your lemon curd and continue to stir for 5-10 minutes on the lowest heat setting or until the mix begins to thicken.
Immediately pour the lemon curd into the pie crust and place your lemon pie into the fridge to set for at least 4 hours or overnight.
To create the aquafaba meringue, start by measuring your aquafaba liquid from 1 tin of chickpeas. Most tins contain a little more than the 125ml you need for this recipe. For best results, add the liquid to a saucepan and reduce it over low heat until you have only 125ml. Through cooking off the rest, the aquafaba becomes thicker and more egg-like, resulting in a better meringue, so don’t skip this step.
Pour your reduced aquafaba into a clean, grease-free mixing bowl alongside the cream of tartar. Place the granulated sugar and water into a non-stick saucepan and bring to a simmer on low to medium heat until it reaches 116°C-118°C (without stirring). In the meantime, whip your aquafaba into stiff peaks using an electric hand mixer. Carefully remove the pie from the tin and place it onto a serving dish.
Pour the hot sugar syrup into the whipped aquafaba and continue to whisk until well combined. Transfer the meringue mixture to a piping bag and decorate your pie. Alternatively, spoon it on top for a more rustic finish. Use a torch to lightly brown the meringue and you’re ready to serve. Stores well in the fridge for up to 3 days.