Mix the flour with 1 pinch of salt. Dig a fountain, put in 1 egg and 125 g of soft butter cut into pieces. Knead the dough quickly, wrap it in cling film and leave it to rest in the fridge for 1 hour.
Wash and remove the roots and 2/3 of the green of the leeks. Wash them and cut them into trunks of about 1 cm. Melt the butter in a sauté pan, add the leeks and sweat them for 10 minutes, stirring.
Preheat the oven to 200°C (th 6/7). Spread the dough, cut 4 circles in it and prick it with a fork. Then, fill 4 tartlet moulds with butter and flour.
In a bowl, beat the eggs with the cream. Season with salt, pepper and nutmeg. Chop the chives, add the chives-
Spread the leek fondue in the tart base, pour the cream over it. Put in the oven and cook for about 25 minutes.