Flamiche

Steps

1. For the pastry, sift 225g plain flour and ½ tsp salt into a food processor. Add 60g butter and 60g lard, then pulse until the mixture resembles fine breadcrumbs. Transfer to a bowl, mix in 50g cheddar cheese, and add 2 tbs water until the dough comes together. Knead briefly on a floured surface until smooth, then roll out thinly to fit a 23cm x 4cm fluted tart tin. Prick the base with a fork and chill for 20 minutes.
2. In a saucepan, melt 75g butter over low heat. Add 1kg leeks and ½ tsp salt, cover, and cook for about 10 minutes until soft. Uncover, increase heat, and cook for another 2 minutes to evaporate excess liquid. Spoon the leeks onto a plate and let cool.
3. Preheat the oven to 200°C (fan 180°C, gas 6). Line the pastry with baking paper and fill with baking beans or rice. Blind bake for 15-20 minutes until edges are golden. Remove paper and beans, then bake for an additional 7-10 minutes until the base is crisp and lightly golden. Set aside and lower the oven temperature to 190°C (fan 170°C, gas 5).
4. In a bowl, combine 300ml crème fraîche, 1 whole egg, 3 egg yolks, and ¼ tsp nutmeg. Mix gently, season to taste, and stir in the cooled leeks. Pour this mixture into the tart case and bake for 35-40 minutes until set and lightly golden. Allow to cool for 10 minutes, then remove from the tin and serve.