Lemon meringue pie sorbet

Method

1. Pour 450ml water into a saucepan and finely grate the zest of the lemons into it. Add 300g of the sugar, then put over a low heat and warm through until the sugar has dissolved.
2. Add the juice of all 4 lemons, then pass through a fine sieve into a container and leave the mixture to cool completely. At this point you can either transfer the syrup into an ice cream machine and churn according to the manufacturer’s instructions, or put the container in the freezer for 4-6 hours until firm, stirring with a fork every hour or so to break up the ice crystals.
3. When the lemon sorbet is very nearly frozen solid, heat the oven to 180°C/160°C fan/gas 4. Put the remaining 75g sugar in a baking tin and toast it for 10 minutes. Add the egg whites to a stand mixer with a whisk attachment (or use a mixing bowl and an electric hand mixer). Beat for a few minutes until the egg whites turn frothy, then add all the hot sugar while whisking constantly. Continue to whisk for about 10 minutes until the meringue forms glossy stiff peaks (that don’t flop over when the whisk is removed).
4. Take about a third of the meringue and beat it into the sorbet (if the sorbet is fully frozen and too stiff to mix, let it soften a little) – this should loosen it up. Carefully fold the remaining meringue into the mixture until just combined, trying not to knock too much air out of it. Return everything to the freezer for at least another 2 hours.
5. Take the spoom out of the freezer for 5 minutes, then serve scoops drizzled with lemon curd and scattered with crushed shortbread, if you like.