1. Preheat oven to 170 degrees Celsius. Grease a 20cm loose bottom tart tin (or four small tartlet tins if making individual tartlets).

2. To make the pastry by hand, sieve together the flour, cocoa powder, sugar and salt into a bowl. Add the diced butter and rub into the flour with your fingertips until the mixture resembles fine breadcrumbs. With a dinner knife, work in the egg yolks then bring together to a firm dough (add a little water if the pastry feels dry, to help the mixture come together). Wrap in clingfilm and chill for 20 minutes.

3. Roll the pastry out on a lightly floured work surface and use to line the tin (or small tins). To bake the pastry blind, line with parchment paper and fill with baking beans. Place in the preheated oven for 20-25 minutes, without the pastry colouring. Remove the beans and paper and set aside.

4. For the passion fruit filling: Set a sieve over a bowl. Cut each passion fruit in half and use a spoon to scrape out the contents (fully ripe fruits will contain moist seeds and some pulp). Use a spoon to press the pulp and passion fruit juice through the sieve and into the bowl (discard the gritty seeds once you are sure you have sieved out as much moisture as possible from them).

Use a fine grater to grate the zest from one lemon. Cut the lemons in half and squeeze the juice from one and a half lemons. In a mixing bowl, combine the passion fruit pulp, lemon zest, lemon juice and sugar, then stir well to combine until all the sugar is dissolved. Lightly break up the eggs with a whisk, then stir them into the fruit mixture, followed by the cream. Mix well with a whisk, skimming away any froth.

5. Pour the mixture into the pre-baked chocolate pastry. Bake in the preheated oven for 20-25 minutes, or until the filling is just set in the centre (once cooked the filling should no longer wobble in the centre). Remove from the oven and set aside in a cool place to cool completely. Serve chilled.

VARIATION

Instead of whole passion fruits, you can use 100ml passion fruit purée. If the purée is sweetened, reduce the quantity of sugar in the filling.