To make the pastry, place the butter, the flour and the sugar in a food processor and process until the consistency resembles fine crumbs. Add the egg and blend to forms a smooth dough ball. Wrap the dough in cling wrap and place in the fridge for half an hour.

Grease a 28cm loose-bottomed cake tin. Roll out the pastry to fit the tin and carefully lift into the tin, moulding the pastry to cover the base and sides of the tin. Loosely place greaseproof paper over the pastry and fill with baking beans. Blind bake the pastry case for 15 minutes. Remove the baking beans and bake for a further 15 minutes.

To make the filling, place the yolks, whole eggs, sugar, vanilla paste, lemon zest and juice into a heavy-bottomed saucepan. Whisk over a low heat until the mixture has thickened. Add the butter and stir with a wooden spoon until melted and combined. Once the mixture coats the back of a spoon, pass through a sieve and whilst still warm, pour into the prepared tart case. Leave to set and cool in the fridge.

When you’re ready to serve, generously sprinkle castor sugar over the top of the tart and brûlée with a blowtorch until caramelized.

Allow the caramelised sugar to cool and harden before serving.