410g tin evaporated milk - that’s been in the fridge overnight
280g dark muscovado sugar
1Heatcoven to 190c
2 Put a baking sheet in the oven to get hot.
3Sieve the flour into a bowl. Using your fingertips, rub in the butter until the mixture resembles fine breadcrumbs.
4Add the egg and 1-2 tbsp water to mix to a firm dough.
5 Wrap in clingfilm and leave to rest in the fridge for at least 30 minutes.
6Roll out the pastry on a lightly floured surface and use to line a tart tin, leaving any excess overhanging the edge. Line with baking parchment, put on baking beans or rice and bake for 15 minutes.
7 Remove the beans and parchment and return to the oven for a further 5-10 minutes until golden. Leave to cool then, using a sharp knife, trim the top of the pastry case.
8Tip the evaporated milk and sugar into a large bowl and, using an electric mixer on whisk together on full power for 15 minutes until the mixture resembles a light coffee-coloured, creamy foam that doesn’t quite hold peaks.
9Pour the mixture into the tart tin and bake for 20 minutes on the hot baking sheet.
10When cooked, the filling should be lightly set and have a sticky surface