PLUM PIE

Ingredients : Flour, for dusting 1 recipe Buttery Pie Dough 3 tbsp. cornstarch 1⁄2 tbsp. fresh lemon juice 1⁄4 cup grape jelly 3 tbsp. sugar, plus 1 tbsp. for sprinkling 1⁄4 tsp. kosher salt 10 ripe plums, pitted and thinly sliced 1 egg, lightly beaten with 1 tbsp. water Instructions : On a gently...