Perfect Rhubarb Pie

Directions

• Place rhubarb in a colander; pour boiling water over rhubarb and allow to drain. In a large bowl, mix sugar, flour and tapioca. Add drained rhubarb; toss to coat. Let stand 15 minutes. In a small bowl, whisk egg and cold water; stir into rhubarb mixture.
• Preheat oven to 400°. On a lightly floured surface, roll one half of dough to a 1/8-in.-thick circle; transfer to a 9-in. pie plate. Trim even with rim. Add filling; dot with butter. Roll remaining dough to a 1/8-in.-thick circle. Place over filling. Trim, seal and flute edge. Cut slits in top. Bake 15 minutes.
• Reduce oven setting to 350°. Bake until crust is golden brown and filling is bubbly, 40-50 minutes longer. Cool on a wire rack.