Place the flour, icing sugar and salt either in a bowl or a food processor and mix. Add the butter and rub in with your fingers or pulse in the food processor until it resembles sand. Mix in the egg yolk then gradually add the cold water until it forms a soft but not wet dough. Wrap in clingfilm and place in the fridge for at least half an hour.

Roll out the chilled pastry on a lightly floured surface until it is large enough to line a 23cm/9in tart tin and no thicker than 5mm. Place the pastry in the tin and gently press it into the corners, do not trim off any overhanging pastry (it helps to stop the pastry shrinking when it is baked).

Place the pastry case in the freezer for at least 15 minutes. Meanwhile, heat the oven to 180C/350F/gas mark 4. Line the pastry case with tin foil or greaseproof paper and fill with baking beans. You only need a single layer of beans across the centre but try to shore up the edges of the pastry case with beans.

Bake for about 25 minutes then remove the beans and foil/paper and turn the oven down to 170C/325F/gas mark 3 and bake for another 15 minutes until the pastry is golden all over.

Use a very sharp serrated knife to trim off any overhanging pastry while it is still warm and in the tin. Allow to cool then remove the pastry case from the tin.

Place the milk and vanilla extract in a saucepan and heat until just boiling. Meanwhile, whisk together the egg yolks and sugar until pale and thickened, then whisk in the flour and cocoa powder until smooth.

Gradually whisk the hot milk into the yolk mixture then return it to the saucepan over a medium/high heat and bring to the boil, whisking constantly. Turn the heat down to low and continue to cook for a couple of minutes, whisking constantly, until very thick.

Whisk in the chocolate until melted and smooth, then pour the mixture into a bowl and cover with clingfilm directly on the surface to prevent a skin from forming, refrigerate until cold. (If the mixture is lumpy at all then you will need to scrape it through a sieve before refrigerating).

Place the tart case on a serving plate. Melt the 50g of chocolate and brush it all over the inside of the pastry case with a pastry brush, set aside until the chocolate has set (this helps to create a barrier between the pastry and the filling to stop the pastry from going soggy).

Once the chocolate has solidified, beat the chilled pastry cream until it is smooth and spreadable, then spread it evenly over the inside of the pastry case. Arrange the strawberry slices in concentric circles on top of the creme patisserie.

Gently heat the apricot jam (either in a small saucepan or in bursts in the microwave) until runny. Pass it through a sieve to remove any pieces of fruit, then brush the strawberry slices with the jam using a pastry brush.

Keep the tart refrigerated, it is best served shortly after filling.