Cut your rhubarb into little chunks â about ¼â â ½â cubes Stir the rhubarb and sugar together and bring to a boil. Boil it for 10 minutes. Stir constantly. Remove from heat and add 1 can of blueberry pie filling. Bring the jam back to a boil. Turn off the heat and stir in a 3-ounce package of Jell-O. Pour the jam into your freezer containers.