Step 1

Make the dough according to the recipe. Let it rest at least 2 hours before rolling. Divide the dough in 1/Roll one piece of dough to a 12" circle. Roll the dough onto the rolling pin to transfer it to a 9" pie plate. There should be at least a 1 inch overhang of dough.

Step 2

Roll the other piece of dough to a 12" circle.Sprinkle the dough with flour, fold in 1/2 then sprinkle and fold again. Place the folded dough into the lined pie plate. Cover the pie with plastic wrap and refrigerate while you prepare the filling. This can be done several hours ahead or the night before.

Step 3

In a large bowl, combine the rhubarb pieces, sugar and lemon zest. Toss to combine. Allow the fruit to macerate at room temperature for 1/2 hour. Sprinkle the corn starch over the filling and toss to combine.

Step 4

While the fruit is macerating, preheat the oven to 350°F. Line a sheet pan with parchment paper.

Step 5

Remove the pie plate from the refrigerator and take out the folded dough. Pour the filling into the pie plate. Brush the edges of the crust with egg wash then place the top crust on the bottom. Press around the edge of the pan to adhere the two crusts

Step 6

Trim the crust to even out the edges. Use your fingers or a fork to crimp the crust. Set the pie onto the parchment lined baking sheet.

Step 7

Use a paring knife to cut an "X" in the center of the pie for a steam vent. Peel back the four pieces to form a opening in the center.

Step 8

Brush the entire surface with egg wash and sprinkle liberally with sugar. Bake the pie on the bottom rack of the oven for about 1-1 1/2 hours.

Step 9

The filling is ready when you can see it bubbling vigorously in the middle opening of the crust.

Step 10

Cool at least 2 hours to allow the filling to set before slicing.