Rhubarb & Rose Meringue Tart

While this is based on Polish Plesniak, rhubarb and meringue are popular all over the Baltic States, so it feels appropriate to include it here. I originally made the dessert for a supper club and when it quickly became a favourite, I developed this vegan version using aquafaba, or chickpea water. For the purest flavour, I would recommend making your own aquafaba; otherwise, a 400 g (14 oz) tin will provide more than enough for this recipe. (The drained ch