Rich Barron, chef-owner of Il Capriccio, in Waltham, came up with this double-crust savory pie filled with garlicky mashed potatoes and Parmesan cheese.
2 cups flour
1 teaspoon salt
1/2 cup unsalted butter, cut up
2 egg yolks, mixed with 6 tablespoons ice water
Extra flour (for sprinkling)
In a food processor, combine the flour and salt. Whir the machine quickly to sift them. Add the butter and whir the machine in on-off motions just until the mixture forms breadcrumbs.
Turn off the processor and sprinkle the egg yolks onto the flour-butter mixture. Work again in on-off motions just until the pastry forms clumps. It should not come together to form a dough.
Turn the pastry out onto a lightly floured board and knead it lightly until it is smooth. If the mixture seems dry, sprinkle it with a few drops of water and cut the water in with a blunt knife (this is more effective than kneading).
Divide the pastry in half, shape each half into a smooth, flat cake, and wrap each in foil. Refrigerate them for 20 minutes.
6 Idaho potatoes, peeled and cut into pieces
1 tablespoon chopped fresh rosemary
1/4 cup whole, peeled garlic cloves, coarsely chopped
1/2 cup (1 stick) unsalted butter, cut up
1 cup heavy cream
1 cup freshly grated Parmesan cheese
3 eggs, lightly beaten
In a large saucepan, combine the potatoes, rosemary, and garlic. Cover with water, then bring it to a boil and let it bubble steadily for 20 minutes or until the potatoes are tender. Drain them in a colander.
Transfer the potatoes to the bowl of a mixer and beat them just to break them up. Beat in the butter, cream, cheese, and eggs until thoroughly mixed.
Let the mixture cool.
Set the oven at 400 degrees. Have on hand a 10-inch pie pan or rectangular baking dish.
To assemble the pie: On a lightly floured board, roll one piece of pastry until it is 12 inches wide. Line it into the pan, letting the edges hang over. Spread the potato mixture in it.
Roll out the other piece of pastry until it just covers the top of the dish. Lay it on the potatoes. Roll up the overhang from the bottom piece until there is a neat roll all around the top edge.
Make half a dozen slits in the top of the dough.
Bake the pie for 15 minutes. Turn the oven temperature down to 350 degrees and continue baking for 50 to 60 minutes or until the pastry is golden brown and firm to the touch.
Let the pie settle for 15 minutes, then cut it into wedges or squares and serve.