For the pastry
For the filling
Make the pastry by sifting the flour into a bowl with a pinch of salt. Add the butter in pieces and rub in thoroughly with fingertips until the mixture resembles fine breadcrumbs.
Stir in the cheese, then the egg yolk. Gather the mixture together with your fingers to make a smooth ball of dough. Wrap the dough in cling film and chill in the refrigerator for about 30 minutes.
Preheat the oven to 200°C/400°F/Gas mark 6.
To make the filling, plunge the courgette pieces into salted boiling water, bring back to the boil, then simmer for 3 minutes. Drain and set aside.
Put the eggs in a jug, and beat lightly together with the cream. Stir in the basil and lime zest, and sprinkle with salt and pepper. Set aside.
Roll out the chilled dough on a floured work surface, and use to line a loose-bottomed 23cm/9in flan tin. Refrigerate for 15 minutes.
Prick the base of the dough with a fork, then line with foil. Stand the tin on a preheated baking sheet, and bake in the oven for 10 minutes.
Remove the foil and brush the inside of the pastry case with the egg white to seal. Return to the oven for 5 minutes.
Stand the courgette chunks upright in the pastry case, then slowly pour in the egg and cream mixture. Return to the oven for 20 minutes until set and golden. Serve hot or cold.