FIRST OF THE SEASON RHUBARB AND STRAWBERRY PIE

makes one 9” lattice topped pie

See NOTE below re: par-baking the crust before filling.
 
All-butter double crust pie pastry:
 
2¼ cups all-purpose flour
1 teaspoon salt
1 tablespoon sugar
7 ounces cold, unsalted butter, cut into ½” cubes
5-6 tablespoons ice cold water
1 tablespoon cider vinegar
 
Place the flour, salt and sugar together in a large bowl; whisk to combine. Using a pastry cutter or your fingers, add the cold butter blending it into the flour until it resembles coarse meal. Sprinkle 5 tablespoons of ice cold water and the tablespoon of vinegar onto the flour/butter mixture. Toss the mixture using a fork or your fingers, mixing just until the dough comes together. (If the mixture feels dry, add up to an additional tablespoon of water.) Divide the dough in half, shape each half into a disc and wrap each half in plastic wrap. Refrigerate for at least an hour before rolling out.
 
On a lightly floured sheet of parchment paper, roll out one portion of the dough into a circle about 12” in diameter and about ⅛” thick. Gently place the dough into a 9” pie plate, being careful not to stretch it. Trim the excess dough so you have a 1” overhang, tuck this/roll this under to create a raised edge. Crimp the edge using your thumb and index finger.  Place the bottom crust in the refrigerator. Note: If time allows, it will significantly improve the crispness of the bottom crust if you par-bake it before filling. This will mean freezing the unbaked crust until it is firm (preferably 15 minutes), removing it from the freezer, lining the pie crust with parchment and filling it with pie weights or beans. place on a baking sheet and bake in a pre-heated 400 degree F oven for 20 minutes. Carefully remove the parchment and weights/beans. Reduce the oven to 350 degrees F and bake for an additional 15-20 minutes, until the dough is no longer raw on the bottom. Let the shell cool completely. It's a little more of an effort to attach lattice to a par-baked crust, but avoiding an under-baked bottom crust is worth the fiddle. 
Roll out the second half of dough for the lattice top on a lightly floured sheet of parchment paper into a circle about 10” in diameter and about ⅛” thick. Use a pastry cutter or a knife to cut ten 1” wide lattice strips. Carefully slide the parchment paper with the lattice strips on to a baking sheet and put it back in the refrigerator to chill while you prepare the filling.

Prepare the egg wash - 1 egg beaten with 1 teaspoon of water and set aside with coarse sugar for sprinkling.
 
Rhubarb-Strawberry filling-
 
1½ pounds rhubarb, rinsed, leaves removed, trimmed and coarsely chopped (you will need 3½ cups)
1 quart fresh strawberries, lightly rinsed, stems removed, cut in quarters (you will need 3½ cups; save any extras for another use)
2 teaspoons fresh orange juice
1 teaspoon fresh lemon juice
1 teaspoon good quality vanilla
1 cup sugar
2 tablespoons dark brown sugar
pinch salt
¼ teaspoon freshly ground cardamom
¼ teaspoon cinnamon
1 teaspoon orange zest
¼ cup finely ground instant tapioca
 
In a large bowl, toss just the rhubarb with the orange juice, lemon juice and vanilla. In a small bowl, whisk together the sugars, salt, cardamom, cinnamon, orange zest and tapioca. Add the sugars/spices/tapioca to the rhubarb and let it sit for 30 minutes to soften the tapioca and the rhubarb. (Save the strawberries; you will add them later.)
 
Preheat the oven to 425 degrees F.  Retrieve the cooled, par-baked bottom pie crust and the baking sheet with the lattice crust strips from the fridge.
Add the strawberries to the rhubarb mixture, using a rubber spatula to gently combine. Place the par-baked pie plate on a baking sheet lined with parchment paper and pour the filling into the pie shell. Brush the top edge of the bottom crust with a little of the egg wash. Place one lattice strip in the center of the pie, then another strip perpendicular to the first strip, forming a “t”. Add the remaining strips to create a lattice. Trim the lattice edges so they are no longer than 1 inch over the pie pan’s edge. Carefully tuck the lattice edges beneath the edge of the bottom crust. Seal the edges together, gently crimping with your fingers so you have a standing edge. Carefully brush the lattice with the egg wash, sprinkling with coarse sanding sugar. Place the pie on a parchment lined baking sheet and bake it on the bottom rack of the preheated oven for 15 minutes. Rotate the baking sheet and bake for an additional 10-15 minutes at 425 degrees. Then reduce the oven temperature to 375 degrees and continue baking for an additional 40 to 45 minutes, covering the edges of the pie with strips of aluminum foil to prevent over-browning. The pie will be golden and the fruit will bubble around the edges and in the center of the pie when it is ready. Remove from the oven and place on a cooling rack. Cool for several hours before slicing. Refrigerate any leftovers.