For the Béchamel:
First, prepare the Béchamel (see p. 50) with the listed ingredients and let cool.
Preheat oven to 180 ° C and grease six individual jelly molds. Meanwhile, cook the leeks in boiling salted water for 10 minutes until tender.
Drain and mash them over a bowl with the potato masher, and add the pine nuts. Mix the preparation with cold béchamel, add the Parmesan and egg yolks, stir and leave the mixture.
Whisk the egg whites to form peaks and add them. Fill the jelly molds with the preparation and bake custards 30 minutes.
Remove from the oven, let stand a few minutes and remove them from the molds to serve.