Silverton's librarian, Jackie Leithauser, turned us on to this sweet-tart combination.
For the Crust
- 2 1⁄2 cups flour
- 1⁄2 tsp. salt
- 3⁄4 cup vegetable shortening
For the Filling
- 2 tbsp. cornstarch
- 1 1⁄4 lb. rhubarb stalks, cut into 1'' pieces
- 3⁄4 cup sugar
- 1⁄2 tsp. lemon zest
- 1⁄2 tsp. ground cinnamon
- 1⁄8 tsp. salt
- 1 cup blueberries (thaw and drain, if frozen)
- 2 tbsp. butter
- 1 egg, lightly beaten
Combine flour and salt in a large bowl. Cut in shortening with a fork until mixture resembles coarse cornmeal. Add 6–8 tbsp. ice water, 1 tbsp. at a time, stirring until dough holds together. Cover and refrigerate for 1 hour.
Dissolve cornstarch in 1⁄3 cup water in a medium saucepan. Add rhubarb, sugar, lemon zest, cinnamon, and salt, and cook, stirring, over medium heat for 2 minutes. Remove from heat, cool slightly, and add blueberries.
Preheat oven to 425°. Roll out dough into 2 12'' rounds on a floured surface. Line a 9'' pie pan with 1 round, add filling, and dot with butter. Cut remaining round into 6 strips, and "weave" a top crust. Brush crust with egg and bake for 10 minutes. Reduce heat to 350° and bake until crust is brown, about 40 minutes.