Boysenberry pie is the best--sweet and tart at the same time with a depth to the flavor.
4 cups boysenberries
3/4 cup sugar
1/4 cup flour
Stir together flour and sugar in a large bowl.
Add berries and toss until the fruit is coated with the mixture. (If frozen berries are used, let them thaw enough so that they pick up most of the flour mixture.)
Pour mixture in pie crust. Top pie with crust. A lattice crust is good because it lets the pie breath well during cooking, increasing the chance that the pie will not be runny. Before cutting pieces for the lattices, brush the dough with egg wash (beaten egg with a little water). Once the lattice is constructed, sprinkle with granulated sugar.
Bake for 50-60 minutes on second lowest rack at 350° until top is golden and filling has started to bubble.