For the pastry, place the flour, butter and salt in a food processor and process until mixture resembles breadcrumbs. Add the egg and then gradually add the water, 1 tablespoon at a time, until the mixture forms a ball.
250 g plain flour, 125 g unsalted butter, Pinch of salt, 1 egg, 3 to 5 tablespoons cold water
Remove the dough and knead on a lightly floured surface for 30 seconds. Shape the dough into a disc, wrap it in cling film and refrigerate for 30 minutes.
To make the pie, roll out the pastry in a large circle to 5mm thickness. Roll the pastry over the rolling pin and unroll it over a 28cm loose-bottomed quiche or tart tin. Lift the pastry into the tin and tuck it against the sides tightly. Cut off the excess pastry by rolling the pin over the top edge of the tin. Gently press the base of the pastry tart again.
Prick the base with a fork, cover loosely with cling film and refrigerate again for 30 minutes.
Remove the quiche base from the refrigerator and line with baking paper. Fill with baking weights, dried beans or raw rice, and blind bake for 10 minutes in a preheated oven at 170°C.
Take the quiche base out of the oven and remove the baking paper and weights. Return quiche tin to the oven and bake for a further 15 minutes or until the base is golden an no longer doughy.
For the filling, heat the olive oil in a large frying pan, add the leek, garlic and lemon rind, and cook over medium heat for 3-5 minutes or until the leeks are soft. Add the wine and simmer for 3-4 minutes or until it’s absorbed. Season to taste with sea salt and freshly ground black pepper, then cool.
2 tablespoons olive oil, 3 leeks, 1 garlic clove, 1 tablespoon lemon rind, 60 ml dry white wine
Lightly beat eggs and milk together in a bowl. Add the leek mixture, Gruyère and pecorino and season to taste.
6 eggs, 125 ml milk, 120 g Gruyère, 120 g pecorino
Pour the mixture in the quiche case. Top with the zucchini flowers, pressing them into the leek mixture gently, and then scatter the top with thyme.
5 to 8 zucchini flowers, 1 tablespoon fresh thyme leaves
Cook the quiche at 190°C for 25 to 30 minutes or until top is golden and firm. Serve warm or cold with a crisp green salad.