Filling:

Mix the rhubarb and strawberries together in a medium-size bowl. Mix sugar, tapioca, flour, and cinnamon together in a small bowl. Set aside.

Prepare crust:

In a large mixing bowl add:

Flour and salt, mix well.

Cut in shortening until pieces are the size of small peas.  Sprinkle in 1 Tbsp of water at a time gently tossing with a fork until the mixture is moistened enough to stick together and form a large ball.

Divide ball in half.

On a floured surface, preferably on a pastry cloth, roll out one ball of dough a little larger than the pie dish you intend to use.

When the dough is placed in the pie dish the bottom crust will need to slightly extend over the edges of the dish. This prevents the fruit juices from leaking under the crust.

Set first rolled out crust in the pie dish. Pour fruit mixture into the dish over the crust. Top fruit mixture with pieces of butter or Earth Balance.

Roll out the second ball of dough for the top crust. Place over fruit mixture in the pie plate. Cut small slits in top crust. Trim edges of crust and flute, by squeezing the bottom and top crust together and pushing between fingers to form an edge.  Then add the trimmed off pieces if you like. Make slits through the top pastry layer to allow steam to escape.

Note ~At this point, I like to cover the edges of my pie with foil for part of the cooking time. This allows me to bake the pie longer and ensure the fruit is fully cooked. It also prevents edges from becoming overdone.