Photo: Kris Kirkham
Pour the cream into a medium pan and add the sugar. Dissolve the sugar over a low heat. Bring the mixture to the boil and boil it for 3 minutes exactly. Take the pan off the heat, stir in the lemon zest and juice, and leave the mixture to cool until lukewarm.
Arrange half the sponge fingers in the base of a trifle bowl; top with 2 tbsp lemon curd in small blobs and sprinkle with half of the limoncello. Add the rest of the sponge fingers and repeat with 2 tbsp of lemon curd and the rest of the limoncello.
Pour the creamy lemon mixture into the bowl on top of the other ingredients. Set aside to cool, then transfer to the fridge for a couple of hours (or overnight) to set.
Toss most of the blueberries with the chopped mint; scatter on top of the set lemon layer.
Mix the Greek yogurt with the rest of the lemon curd; use to top the trifle. Scatter with the remaining blueberries and mint sprigs.
Get ahead: Make up to the end of step 3 the day before so you can cover and chill overnight.