The recipe for the gf pie crust you can find here.
The filling is also a cinch to make. Your family and friends will think you slaved all day in the kitchen, when you didn't. Let them think that though!
In a medium saucepan place:
1 1/2 cups halved strawberries
2 cups mulberries, rinsed
1/2 cup blueberries (I used frozen)
Add to this 1/2 cup cold water
1/4 cup cornstarch
I know this is a lot of cornstarch but you want this mixture to set up nice and firm so you don't have to bake it.
On medium heat bring fruit mixture to a boil, stirring constantly when it starts to bubble and thicken. Cook for about one minute more.
Allow to cool for 5 minutes and pour into pie shell. You can serve this once it cools to room temperature or you can put in the fridge to speed up the process. Slice and serve.