Knead the first 3 products + 3 tablespoons water into a smooth dough and leave it briefly in the fridge. In the meantime, sauté the finely chopped leeks in butter for about 20 minutes. Occasionally, stir it.
Once you remove it from the heat and it cools, add the eggs, cream, chopped ham, grated cheese, salt, pepper and a little nutmeg. Divide the dough into 2 parts. In a buttered baking dish, lay out one part, pulling it to the walls of the dish as well. Add the filling on top and cover with the second pulled crust, pinching the edges of the bottom with that of the upper crust, so the filling does not spill out.
Brush the top with beaten egg yolk with a little water and put the leeks pita to bake in a pre-heated oven at a moderate temperature for about 30 minutes.
The leeks pita is equally delicious whether hot or cold.