Preheat oven at 200° C.
Cut the leeks into slices, scald them in a wide saucepan in about an inch of boiling water.
When they absorb the water, sauté the leeks in the butter and add the ham, graviera and emmental cheese, the eggs well beaten and finally the salt and pepper.
In a buttered long and narrow pyrex spread the pastry so that it stands out a bit.
Add the leek mixture and pour over the fresh cream.
Bake for 45 minutes.