Mix in a large bowl about a quart of blueberries, 1/2 to 3/4 cup of white granulated sugar (depends on you and how sweet you want the pie to be), 3 Tablespoons of all purpose flour, and a little water (just enough to get the ingredients wet. I would say about a Tablespoon).
Make sure all ingredients are incorporated together. Place a Pilsbury crust into a pie pan. Pour mixture into the crust. Top with pie crust. Put foil around the edges to prevent burning.
Bake in a preheated 350 degrees for 45 minutes. Remove the foil for the last 5 minutes of baking add butter to the top and sprinkle with sugar. Bake the last five minutes and remove.
Cool before serving to allow pie to “set”. Good served alone or with ice cream.