• 2 round, puff-pastry crusts, uncooked
• 3 tablespoons butter
• 2 pounds (or more) leeks, cleaned and cut into 1/4 inch rounds (don't use the tougher dark green part)
• 3 tablespoons flour
• 2 cups milk
• 1/4 cup grated gruyère or similar cheese (optional)
• salt and pepper
• 1/8 teaspoon nutmeg
• 1 egg yolk

Stir in the flour until mixed completely with the leeks. Pour in the milk and cook, stirring occasionally until the mixture thickens and comes to a boil - about 5 minutes. Remove from heat and let cool about 5 minutes. Stir in nutmeg and salt and pepper to taste.

Meanwhile, line a 9 inch tart or pie pan with one of the crusts. Brush the bottom of the crust with the egg yolk mixed with a couple of teaspoons of water. Pour the cooled leek mixture into the crust and top with the second crust. Roll the edges together so that the whole tart is sealed. Make a hole in the center of the tart so that steam can escape as the tart is cooking and, if you wish, make a design on the top crust with a sharp knife.

Bake for 30 minutes at 375° F. Serve warm.

Makes 6 servings.