Sarah Tuck's Christmas Mille-Feuille

Heat 1½ cups of the milk, lemon zest and sugar in a saucepan over a medium heat, whisk to dissolve sugar and bring to a simmer. While the milk is warming, whisk together the remaining milk with the egg yolks, vanilla extract, flour and cornflour until the mixture is a thick smooth paste. Add a third of the milk to the egg mixture, whisking constantly. 

Pour the milk and egg mixture back into the remaining hot milk and continue whisking really hard over the heat until the custard is really thick and smooth. Remove from the heat, pour into a container and stir through the lemon curd. Cover the surface with plastic wrap and chill. 

Preheat oven to 200˚C (400˚F) and line a baking tray with baking paper. Lay half of the puff pastry on top, prick all over with a fork (this is crucial!) and top with more baking paper and another baking tray. Cook for 9 minutes, flip trays over and cook a further 9 minutes. Repeat with the remaining pastry. 

Once the pastry has cooled, trim into rectangles – this is much easier than you might imagine. Trim the outside edges evenly with a serrated knife, then confirm (using a ruler) how many you can cut, use the ruler for each slice so that they are all the same size. When cooked, I cut the sheets of pastry into 24 even rectangles about 5.5cm x 10cm. The dimensions don't really matter as long as they are all the same.

To construct, just pop the bottom layers onto serving plates. Spoon creme patisserie on top and smooth evenly, but don't squash and don't go right to the edges of the pastry. Top with another layer and repeat. 

Dust with icing sugar and serve with fresh fruit on top or alongside. Makes 8.

You wouldn't think so, but you can actually make these and refrigerate them up to a couple of hours before serving – just dust with icing sugar at the last minute and make sure they look even.