Roll out the dough to line a 10 1/2-inch tart pan. Carefully transfer the dough to the pan. Chill for another 30 minutes, or until firm.
03Preheat the oven to 425 degrees.04Trim the leeks at the root. Cut off and discard the fibrous, dark green portion. Split the leeks lengthwise for easier cleaning and rinse in cold water until no grit appears. Coarsely chop the leeks.05Melt the butter in a medium saucepan over low heat, add the leeks, salt and pepper and cook, covered, until the leeks are very soft, about 20 minutes. They should not brown.06If the leeks have given up an excessive amount of liquid, drain them in a colander. Combine the eggs and creme fraiche in a medium-size bowl, mixing until thoroughly blended. Add the leeks and mix again. Reserve a quarter cup each of the cheese and the ham to sprinkle on top of the tart. Mix the rest into the leek mixture.07Pour the leek mixture into the prepared tart tin. Sprinkle with the ham, then the cheese. Season generously with freshly ground black pepper.08Bake until nicely browned, 40 to 45 minutes. Serve warm or at room temperature.