For the rough puff pastry
150g plain flour, plus extra for dusting
25g butter, chilled and cut into cubes
50 – 75ml chilled water
60g butter, frozen then grated
For the custard
375ml whole milk
45g plain flour
2 strips of pared lemon zest
1 cinnamon stick
375g caster sugar
7 large egg yolks
Step 1 – For the pastry, mix the flour and salt together in a bowl. Rub in the chilled butter using your fingertips until the mixture resembles breadcrumbs. Gradually add enough water to form a dough (about 4-6 tablespoons of water).
Step 2 – Roll the dough out into a rectangle on a lightly floured work surface. Grate half of the frozen butter over the bottom two thirds of the dough. Fold down the top third and fold up the bottom third as if folding a letter.
Step 3 – Turn the folded dough through 90 degrees and roll it out into a rectangle again. Repeat the process of adding the remaining frozen butter and fold as before. Wrap the dough in cling film and leave to rest in the fridge for 20 minutes.
Step 4 – Roll and fold the pastry twice more, then wrap the dough in clingfilm and leave to rest in the fridge for 20 minutes.
Step 5 – Roll the pastry out on a lightly floured work surface to a rectangle measuring 20cm x 30cm. Roll the pastry tightly, from the short side, into a log and cut the log into 12 even sized rounds.
Step 6 – Place one disc into the cup of a 12 hole muffin tin, swirl-side up. Using wet fingers, carefully press the pastry up the sides with your fingers, working from the centre out, until the pastry just pokes over the top. Repeat with the remaining pieces of pastry. Chill for 20 minutes.
Step 7 – For the custard, pour the milk into a pan and whisk in the flour. Add the strip of lemon zest and cinnamon stick. Bring to a simmer, whisking continuously. Cook for 2-3 minutes until thick. Remove from the heat.
Step 8 – Tip the sugar into a small pan with the water. Heat gently to melt the sugar, then increase the heat and boil until the syrup reaches the short thread stage (106C – 112C). Gradually whisk the boiling syrup into the milk mixture.
Step 9 – Put the egg yolks in a large bowl and strain over the milk mixture, whisking continuously until combined. Place a sheet of clingfilm over the surface and leave to cool. Once cooled, remove the strip of lemon zest and cinnamon stick.
Step 10 – Heat the oven to 240 top/bottom heat. Pour the custard into the pastry cases to 1cm below the top, then bake in the oven for 15 -18 minutes until the pastry is golden and crisp and the custard is bubbling with tiny brown spots.
Step 11 – Remove from the oven, cool in the tin for 5 minutes, then gently turn out the tarts and leave to cool on a wire rack.