To make the pastry first cube cold butter, add to a food processor with the flour, ginger and salt pulse until a breadcrumb texture, then stir in the sugar, add the egg and pulse again till it forms a ball of dough. Add 15ml of water to aid it combining, and pulse again.
Form into a smooth round on a floured surface, wrap in cling film and chill for 30 minutes in the fridge.
Heat oven to 200C.
Roll out the pastry on a floured surface to the thickness of 3mm. Use to line five the tart pans and chill again for 15 minutes in the fridge.
Then line them with greaseproof paper and a layer of baking beans, bake for 15 mins. Remove the paper and beans, then return to the oven for 5 mins until pale golden in colour. Leave to cool.
For the filling, cut the passion fruit in half, then scoop the pulp of 8 into a sieve over a bowl. Pass through the sieve using a spoon. Discard the seeds. You should have 80ml passion fruit juice in total. Juice the oranges to make up 70ml. In total you need 150ml combine of fruit juices.
In a pan, mix the cornflour with the sugar, then gradually stir in 200ml cold water followed by the both fruit jucies'. Whisk over medium heat, until the mixture boils and thickens. Take the pan off the heat and whisk the eggs yolks into it.
Once cooled 10 minutes spread the filling over the pastry base.
Reduce the oven to 180C.
For the meringue, whisk the egg whites into stiff peaks, then gradually whisk in the sugar until thick and glossy.
Spoon the meringue over the filling, starting from the pastry edge and working your way into the middle, then gently swirl the spoonfuls together. Bake for 20 mins until the meringue is lightly golden.