The French puits d’amour means ‘wells of love’ – which says it all.
Make the pastry. In a large bowl mix the flour and salt together. Using the coarse side of a cheese grater, grate long lengths of the frozen butter onto the flour. Mix with a palette or butter knife.
Sprinkle 6 tablespoons of the chilled water into the bowl and, using the knife, mix until the dough begins to hold together. Quickly bring the pastry together with a floured hand. (Add the remaining water, if necessary, to bring it into a soft, single lump.) Shape into a flat rectangle of about 15 x 10cm. Wrap in cling film and chill for 30 minutes.
Unwrap the pastry and place on a lightly floured worktop. Roll into a narrow rectangle of about 36 x 12cm. With the short end of the pastry closest to you, fold up the bottom third of the pastry onto the middle third, then the top third down, as if you were folding an A4 letter. Wrap the pastry in cling film and chill again for 30 minutes. Repeat the roll and fold once more, then chill again for at least 30 minutes, or until needed.
For the compote, tip the strawberries into a pan with the sugar and lemon juice and cook over a medium heat for 10 minutes. Add the raspberries and cook for a further 5–10 minutes, until reduced to a thick compote (but not a jam). Remove from the heat, cool, then chill.
For the crème pâtissière, put the milk in a pan with the vanilla pod and seeds. Bring to the boil, then remove from the heat. Whisk the sugar, yolks and cornflour together in a large bowl. Whisk a little hot milk into the sugar and egg mixture, then whisk in the rest of the hot milk until well combined. Return to the pan. Cook over a gentle heat, stirring, until the mixture thickens.
Remove from the heat and pass through a sieve into a clean bowl. Add the butter and stir until melted. Leave to cool, cover with cling film and chill until cold.
Heat the oven to 220°C/200°C fan/425°F/Gas 7. Lightly dust your worktop and roll out the rough puff to a 35cm square. Using the 10cm cutter, cut out 9 discs. Place on the baking sheets and prick each disc all over with a fork. Chill for 30 minutes.
For the choux pastry, place the butter, salt and 150ml of water in a medium pan. Heat gently to melt the butter, then bring to the boil. Immediately remove from the heat and tip in the flour. Beat with a wooden spoon to form a smooth ball of dough that leaves the sides of the pan.
Vigorously beat the egg into the hot dough, a little at a time, until the dough is stiff and glossy. You may not need all the egg – stop if the dough becomes loose. Spoon the mixture into a piping bag fitted with a 1cm plain nozzle.
Pipe the choux in a circle ½cm in from the edge of each disc. Brush each choux ring with beaten egg and sprinkle with nibbed sugar. Bake for 20–25 minutes, until puffed, crisp and golden. Remove from the oven and transfer to a wire rack to cool completely.
To assemble, spoon the crème pâtissière into a piping bag fitted with a 1.5cm plain nozzle. Spoon the strawberry compote into the pastry shells and pipe the crème pâtissière over the top. Sprinkle half a teaspoon of demerara sugar on top and, using a blowtorch, brûlée the sugar. Serve immediately.