| Preheat oven to 400°F |
| Roll out both crusts; line a 9-in pie plate with one |
| Set a rimmed baking sheet on the rack below to catch drips |
| 1 1/4 cups sugar | toss, let stand 15 min | fill bottom crust, dot with butter, top, crimp, cut vents | brush top, sprinkle | bake 400°F 20 min, then 350°F 40 to 50 min, until bubbling | cool on a rack at least 2 hr to set |
| 1/4 cup quick-cooking tapioca |
| 1/4 tsp table salt |
| 3 cups rhubarb, sliced 1/2 in |
| 3 cups strawberries, hulled and sliced |
| 1 double crust pastry for a 9-in pie |
| 2 Tbsp butter, cut in small pieces |
| 1 large egg, beaten |
| 1 Tbsp coarse or granulated sugar |