Rhubarb and Roasted Strawberry Pie

Preparation

1. Prepare the crust:

   1. Step 1

      Put the water in the freezer. Whisk the flour, sugar and salt in a large bowl. Add the butter and shortening and cut into the flour using a pastry blender or two forks or two knives until the mixture resembles coarse crumbs with some pea-sized pieces, which will make your crust flaky. There will still be loose flour and that’s as it should be.

   2. Step 2

      Add the water from the freezer all at once and mix with your hand, fingers spread wide, occasionally squeezing and gently kneading the mix together to incorporate the dry loose bits. The dough should not feel dry and should come together in one shaggy mass. If it doesn’t, add more cold water 1 tablespoon at a time, mixing between each addition to allow the flour to hydrate. The dough also shouldn’t end up sticky or wet; it’s ready when it just holds together.

   3. Step 3

      Cut the dough in half and pat each piece into a 1-inch-thick disk, gently squeezing in the sides as you pat down to prevent cracked edges. Wrap each disk in wax paper or plastic wrap. Refrigerate until it’s firm like cold butter but is not rock hard, 1 to 2 hours.

2. While the dough chills, start the filling:

   1. Step 4

      Heat the oven to 425 degrees with a rack in the lower third. Spread the whole hulled strawberries on a parchment paper-lined sheet pan. Roast until the berries are deeply browned on the bottoms and their juices release, about 30 minutes. Cool completely. If you plan to freeze the whole pie to bake later (see step 8), turn off the oven.

   2. Step 5

      If the dough has gotten too hard to roll easily, let it sit at room temperature for 15 to 30 minutes. Roll a disk of dough on a floured surface using a floured rolling pin into a 12-inch round (see Tip). Loosely roll the round around the pin, then unfurl it over a 9-inch standard glass or dark metal pie dish. Gently press it into the bottom and sides of the dish without stretching it, then refrigerate it uncovered. Roll the other dough disk in the same way, but unfurl it onto a large plate before refrigerating it.

3. Finish the filling:

   1. Step 6

      Taste a strawberry. If it’s quite sweet, use 1 cup sugar. If it’s bland or sour, use 1¾ cups (or any amount in between to your taste). Whisk the sugar, cornstarch and salt in a large bowl. Zest the clementine over the mixture and whisk to coat. Add the rhubarb and mix or toss to coat. Squeeze 1 tablespoon juice from the clementine into the bowl and add the strawberries, leaving behind any pan juices. Gently mix until the berries are evenly dispersed.

4. Assemble and bake:

   1. Step 7

      Scrape the filling into the chilled bottom dough, pressing it firmly to eliminate any gaps. It will mound over the rim of the plate. Scatter the butter bits over the filling. Flip the other dough round on top, centering it. You should have about an inch overhang all around; trim any extra long overhang with kitchen shears.

   2. Step 8

      Fold the overhang under to align with the edge of the dish. Crimp the edges with your fingers or a fork and decoratively flute the edges if you’d like. If you want to make this ahead, freeze the whole pie until very firm, at least 1 hour and up to 1 week (once firm, wrap tightly in plastic wrap). The pie can be baked directly from the freezer. 

   3. Step 9

      Brush water all over the top and sprinkle with sugar. Use a sharp paring knife to cut 8 to 12 slits on top along the lines where you’ll want to slice the pie later. Place the pie on a parchment-lined sheet pan to catch drips.

   4. Step 10

      Bake the pie on the low rack at 425 degrees for 30 minutes, then reduce the heat to 375 degrees and bake until the crust is golden brown and the juices are thick and bubbling, about 45 minutes longer (or 1 hour to 1 hour 15 minutes if baking from frozen). If your pie is browning unevenly, rotate the pan halfway through.

   5. Step 11

      Cool on the pan on a rack for 10 minutes, then carefully move just the pie dish to the rack. Cool for at least an hour to serve warm with a very runny filling. For a sliceable filling, cool until room temperature, 4 to 5 hours. Either way, cut into wedges along the vents. Vanilla ice cream is great on top.