leek and mushroom quiche

INGREDIENTS

• 1 1/4 cups all-purpose flour
• 1/2 teaspoon salt
• 1/4 teaspoon sugar
• 1/2 cup (1 stick) unsalted butter, chilled and cut into small pieces
• 2 to 3 tablespoons ice water
• 3 to 4 leeks, white part only, sliced
• 1/2 cup water
• Salt
• 3 tablespoons butter
• 5 to 6 large white mushrooms, sliced
• 1 tablespoon port
• 3 eggs
• 1 1/2 cups whipping cream (Deb: I use whole milk)
• An 8-inch partially-cooked pastry shell on a baking sheet
• 1/4 cup grated Swiss cheese
• 1 tablespoon butter cut into pea-sized dots