Rhubarb Pie

Name: Rhubarb Pie
Prep time: 20 min
Total time: 20 min
Ingredients: 2 lb. rhubarb cut into 1" pieces (about 7 cups); 1 1/2 c. granulated sugar; 1/4 c. cornstarch; 1 tbsp. lemon juice; 1/4 tsp. kosher salt; 2 batches pie dough; All-purpose flour, for rolling; 2 tbsp. butter, cold and cubed; 1 large egg, lightly beaten with 1/2 tsp. water; Sanding sugar, for sprinkling