Ready in 50 Minutes
• 200g plain flour, plus extra for rolling
• 125g butter, cut into cubes
• 1 large egg yolk, plus 3 whole eggs
• 500g Leeks, thinly sliced
• 300ml single cream
• 2 tsp chopped fresh thyme
• 125g Gruyère, grated
1. Pre-heat the oven to 200C/180C Fan/Gas 6. Sift the flour and a pinch of salt into a large bowl. Rub 100g of the butter into the flour.
2. Mix the yolk with 2 1/2 tbsp cold water and add to the flour mixture. Mix until it starts to form clumps – add a few drops of water if needed. Gather into a dough.
3. Lightly dust a work surface and rolling pin with flour. Roll out the pastry. Use to line a 20-23cm flan tin. Prick with a fork.
4. Lay a piece of foil in the pastry case and weigh down with a handful of uncooked rice. Bake for 10 minutes, remove the foil and rice, then bake for another 5 minutes. Reduce the oven to 180C/160C Fan/Gas4.
5. Melt the remaining butter in a large pan, add the leeks and stir. Cover and gently cook for 5 minutes, stirring occasionally. Remove the lid and cook, uncovered, for another 10 minutes, stirring often, until the leeks are soft.
6. Beat together the eggs and cream, and season with pepper. Stir in the leeks, thyme and 2/3 of the cheese.
7. Pour the mixture into the flan case and sprinkle on the rest of the cheese. Bake for 25 minutes or until the filling is just set.