Measure 4 cups of berries (rhubarb, blueberries, black raspberries, blackberries or whatevere you have on hand) in a bowl. Add sugar - the amount depends on the tartness of your fruit. Mix gently. Add tapioca. Let sit.

Make pie crusts (two) from scratch or buy prepared crusts.

LIne pie plate and fill with berry mixture. Can dot with butter and nutmeg if desired. Top with upper crust. 

Bake in a preheated over at 400 degrees for ten minutes. Reduce heat to 350 degrees and continue to bake for 25-30 minutes more until crust is browned.

I was first introduced to this pie while traveling in Canada. You made use of whatever fruit was in season. Absolutely delicious! Strawberries are another option.

The difficulty lies in making the pie crust - most people have a favorite recipe so I did not include mine.