In a saucepan combine the grapes, sugar and cinnamon. Mix together and let sit for 25-20 mins.
As grapes are sitting, this is a great time to make your pastry!
Combine cornstarch, lemon juice, lemon peel and stir into the grape mixture.
Bring to a boil and let cook for 2-4 minutes, stirring constantly. Grape mixture will thicken.
Line a pie plate with pastry for the bottom crust and pour grape mixture into pie dish. Dot with butter and cover with remaining pastry.
Trim and seal crust, cut vents on top and loosely cover edges with foil.
Bake at 425 for 20 minutes then reduce the heat to 350, remove foil and bake for 35-40 minutes more.
Remove and let cool completely and enjoy!