I married into this pie - so to speak - and oh, I'm so glad I did. You've probably never heard of a grape pie - it does sound weird, doesn't it? But if you can find Concord grapes where you are, you should make this. It's like grape juice in pie form, and it's delicious. It tends toward the sweet, so it's best with vanilla ice cream or, in a pinch, whipped cream.
Concord grapes have a really short season here in Seattle, so grab the grapes when you see them! The season is usually sometime in September, but the weather has been so weird this year that I'm keeping an eye out now. Alas, Concord grapes are not seedless, so you have to get the seeds out of them before you can make the pie. Just put on some comfy shoes and some good music and you'll be done in no time!
Bonus: if you want to be able to make this pie when the grapes are not in season, you can can the filling in a hot water canner - just omit the flour and butter. When you open the jar to make the pie, stir in the flour, and then add the butter and dump the whole thing into the pie crust. It works great!