Masterclass custard slices

Sift the flour and 1/4 level tsp salt into a large bowl. Cut the butter into 1cm cubes and stir into the flour. Add 5 tbsp chilled water and mix with a round-bladed knife until the dough comes together in flakes (there will be some dry mixture left at the bottom of the bowl). Sprinkle on another 2-4 tsp chilled water, a teaspoon at a time, until it’s absorbed.

Next, gather the dough together, handling it as little as possible so you don’t make the butter soft. Shape into a rectangle about 12cm x 17cm. Wrap in cling film and chill for 30 minutes.

Put the pastry on a floured surface with the short side facing you. With a rolling pin, press ridges all the way along. Roll out, rolling it away from you, into a rectangle three times as long as it is wide. Try to make sure the edges and corners stay neat.

Fold the bottom third over the middle, then fold the top third over. Turn the pastry 90 degrees so that the side showing layers is facing you. Press the edges with the rolling pin, then repeat the rolling and folding. If any butter breaks through, dust it with flour. Make sure that the butter doesn’t become soft. Wrap in cling film and chill for 30 minutes. Repeat with another two rollings and foldings as before. Wrap and chill for 30 minutes.

Pre-heat the oven to 220C/200C Fan/Gas 7. Roll the pastry out on a floured surface to the thickness of a pound coin. Trim the edges, cut into 8 rectangles and put on a baking tray. Prick with a fork. Bake for 10 minutes. Allow to cool.

To make the custard, whisk together the yolks, caster sugar, 4 tbsp milk, the cornflour and 10g plain flour until smooth. Heat the remaining milk until hot but not simmering. Gradually add to the yolks in a thin stream. Pour into a pan and cook over a low to medium heat, stirring continuously, until it comes to the boil. Make sure the wooden spoon goes right into the corners of the pan. If the custard starts to form lumps, whisk with a wire whisk until smooth. Add the vanilla extract. Pour into a bowl and cover the surface with clingfilm. Cool, then whisk until smooth.

Cut each pastry slice in half through the middle. Pipe or spoon in the custard.

Mix the icing sugar with 2-3 tsp warm water to make a coating icing. Colour a little of the icing pink and put in a piping bag. Spread white icing on the slices and immediately pipe four lines of pink across each. Run a skewer through the lines for a feathered effect. Leave for 15 minutes to set.