STEP ONEPREPARE recipe for double crust pie, using a 9-inch pie plate. Roll out dough for bottom crust and place in pie plate according to recipe directions. Do not bake.
STEP TWOROLL remaining dough; cut into 1/2 to 3/4-inch strips for lattice top. Chill strips.
STEP THREEHEAT oven to 400ºF.
STEP ONECOMBINE rhubarb and sugar in large bowl. Mix well. Stir in flour. Spoon into unbaked pie crust. Dot with butter. Moisten pastry edge with water.
STEP TWOWEAVE strips of dough over filling to form lattice crust, extending ends of strips beyond edge of bottom crust. Trim ends of strips even with outer edge of bottom crust. Lift edge of bottom crust; fold over ends of strips. Crimp edge.
STEP ONEBRUSH dough with milk. Sprinkle with sugar. Cover edge with foil to prevent overbrowning.
STEP TWOBAKE at 400ºF for 20 minutes. Reduce oven temperature to 325ºF. Remove foil. Bake an additional 30 minutes or until filling in center is bubbly and crust is golden brown. Cool until barely warm or to room temperature before serving.