Start with the pastry. Take half of it and roll it out to a thickness of 2mm, using icing sugar instead of flour, and place on a baking tray lined with greaseproof paper. Place another layer of paper on top of the pastry and then something heavy like another baking tray. This will prevent it puffing up too much. Bake for 15-20 minutes until it’s golden brown.
Remove from the oven and immediately cut 3 rectangles, 6cm wide by 12cm long. It must be hot when you cut the pastry, otherwise it will break and crumble.
Now make the crème patisserie. Add the milk and vanilla seeds into a pan and bring to the boil, then keep aside.
Whisk the eggs and sugar vigorously until pale and fluffy, and then add the corn flour and fold in with a spatula. Slowly pour in hot milk whilst whisking and then put the mix back in the pan and cook on a very low heat till the mix is very thick, stirring every so often.
Remove from the heat and mix into the cold butter. Allow to cool on the side before putting the fridge, covered with clingfilm, for an hour to set.
When set, whip it for a minute and transfer to a piping bag.
To serve, place one piece of puff pastry on your serving plate and pipe 2 lines of crème patisserie along it before placing a layer of strawberry slices. Repeat the process in reverse.
For the ultimate presentation, place your chopped strawberries in a perfect circle around the dessert. Garnish the dish with a few tiny lemon verbena leaves.