Cheese, Ale and Potato Pie

Two 14-ounce packages all-butter puff pastry, chilled

• 2 1/4 pounds medium Yukon Gold potatoes

Kosher salt

Pepper

• 3/4 cup ale, such as Bass
• 1 cup plus 2 tablespoons heavy cream
• 15 ounces sharp cheddar cheese, shredded (5 cups)
• 3 large egg yolks, plus 1 large egg, lightly beaten
• 1 1/2 tablespoons Worcestershire sauce
• 1 1/2 teaspoons Dijon mustard

1. On a lightly floured work surface, roll out each puff pastry sheet to a 10-by-14-inch rectangle. Stack the pastry sheets
2. In a large saucepan, cover the potatoes with 1 inch of water. Add salt, bring to a boil and cook over moderately high heat until the potatoes are just tender, about 15 minutes. Drain and cool under running water. Pat the potatoes dry, then peel and quarter. Gently crush with your hand or a wooden spoon.
3. In a medium saucepan, boil the ale over high heat until reduced to 1/3 cup, about 5 minutes. Add the cream and
4. Arrange 1 chilled puff pastry sheet on a rimmed baking sheet lined with parchment paper and brush with some of the beaten egg. Spread the potato filling on top, leaving a 1/2-inch border all around. Top with the second sheet of puff pastry and press the edges together to seal; crimp decoratively. Brush the top of the pie with more of the beaten egg and cut a few slits for venting. Refrigerate until firm, at least 30 minutes.
5. Preheat the oven to 400°. Bake the pie for 25 minutes. Reduce the oven temperature to 350°, rotate the baking sheet and bake until the pastry is browned and the filling is bubbling, 25 to 30 minutes longer. Let cool slightly before serving.