Created by Teejay on May 2, 2016
Step 1: Position a rack in the center of the oven and heat the oven to 375°F. In a large mixing bowl, combine the rhubarb, strawberries, sugar, all the tapioca, orange juice, zest, cinnamon, clove, allspice, and salt. Toss gently to mix well, and then let sit for at least 10 minutes and up to 30 minutes (while you roll out the bottom crust).
Step 2: Fit bottom pastry into a 9-inch Pyrex pie plate. Pour the filling into the pie shell and dot the top with the cold butter. In a small bowl, beat the egg yolk with 1 tsp. water. Brush the edges of the pie shell with some of the egg glaze.
Step 3: Set the top crust over the fruit filling to form a top crust. Press the edges of the dough together to seal the crust, trim the overhang to 1/2 inch, and fold it under. Flute or crimp the dough all around. Brush the top crust with the remaining egg glaze (you won’t need all of it). Cut four 1- to 1 1/2-inch-long steam vents in the top crust.
Step 4: Set the pie on a foil-lined rimmed baking sheet and bake until the pastry is golden brown and the fruit juices bubble thickly out of the pie, about 50-60 minutes (may need more time depending on your oven). Transfer to a rack and let cool completely before serving, about 4 hours.