Combine the strawberries and rhubarb in a large bowl. Add the sugar, arrowroot and spices and, using your hands (or a wooden spoon), gently toss the fruit and the dry ingredients together until the fruit is nicely coated and the arrowroot has completely dissolved.

Place one rolled out sheet of dough in the bottom of the plate or half sheet pan as per the above instructions. Add the filling. Dot the top of the filling with the butter, and continue to follow the off the charts flaky pie dough instructions for prepping and baking your pre-baked pie.