Step 1 of 10
Flamiche
Sift the flour and ½ tsp of the salt into a food processor, add the 2 oz of cold butter and the lard, and pulse briefly until it looks like fine breadcrumbs.
Step 2
Tip it into a bowl, stir in the grated cheddar, and add just enough cold water for the dough to draw together. Knead it briefly on a floured surface until smooth.
Step 3
Roll the pastry out thinly and line a 23 cm loose-bottomed fluted tart pan, pressing it into the flutes. Prick the base with a fork and chill it for 20 minutes.
Step 4
Melt the 2 3/4 oz of butter in a saucepan over low heat, add the sliced leeks and the remaining ½ tsp salt, cover, and cook for 10 minutes until soft.
Step 5
Take the lid off, turn the heat up and cook for 2 minutes more, stirring, until the liquid the leeks released has gone. Spread them on a plate to cool.
Step 6
Heat the oven to 400°F/350°F fan/gas 6. Line the chilled case with baking paper and beans and blind bake for 15–20 minutes, until the rim turns the color of a cookie.
Step 7
Lift out the paper and beans and give the case another 7–10 minutes, until the base is dry and lightly golden. Set it aside and turn the oven down to 375°F/350°F fan/gas 5.
Step 8
Beat the crème fraîche with the whole egg, the yolks and the nutmeg, season, then fold the cooled leeks through.
Step 9
Spoon the filling into the pastry case and bake for 35–40 minutes, until the center is just set with the faintest wobble and the top has colored.
Step 10
Let it rest for 10 minutes before lifting it out of the pan, or the custard will still be too soft to slice cleanly.
