Double 9" Pie Crust of your choice, I recommend Dorie Greenspan's Good For Almost Everything Pie Dough from from Baking From My Home to Yours*
1 cup Sugar
Zest from 1 Lemon
1/2 teaspoon Vanilla
2 tablespoon Flour
1 tablespoon Minute Tapioca
2 cups chopped Rhubarb (4-5 medium stalks)
2 pints Blueberries
1 tablespoon Water
Preheat oven to 425 degrees. Lightly grease a 9" pie tin and place your rolled** out pie crust inside the tin.
Put the sugar in a large bowl. Zest the lemon over the sugar, then rub the zest and sugar together with your fingertips. Stir in the vanilla, egg, flour and tapioca until a paste forms. Pour in the fruit, and gingerly stir until the fruit is coated fairly evenly. Next, dump the fruit into the uncooked pie shell. Roll out the remaining pie crust, top off your pie and crimp the edges. Combine the remaining egg with the water in a small bowl, then brush the top of the pie with the egg wash and sprinkle with coarse sugar.
Place a foil collar around the crust, and bake on the middle rack for 15 minutes, then reduce the heat to 375 and bake for 45 to 50 minutes.
*If you are just starting out baking or even a seasoned pro, check out Dorie Greenspan's book. It has definitely upped the ante on my baking skills. She explains everything so well it feels like she is there in your kitchen helping you create a baking masterpiece.
**My friend, Jamie, shared a tip for rolling out pie crust. Place the dough between two sheets of wax paper to roll it out, then when you are ready to put the crust in the tin, remove one sheet, flip it over and fit it in place. I can't tell you how many times I have pieced together pie crust when trying to fit it into the pie plate.