Preheat the oven to 375F.
Add the flour, sugar and salt to a Cuisinart and pulse to combine. If you don't have one, use a hand mixer or pastry cutter. Add the butter and shortening and "cut" in (using short pulses) until the mixture is crumbly like a coarse meal. There should be some small pea-sized pieces of butter visible. Add 2 tablespoons of the cold water and pulse a few times to combine. Add 2 more tablespoons of water and blend until the dough starts to stick together. Don't overmix.
Pull the dough together and cut it in half. Form each half into a flat wheel. If the dough is too soft to handle refrigerate for about 4 hours (if you have the time overnight is always best). Once the dough is firmer, pull it from the fridge and start to roll.
Take one wheel of dough and place it on a well-floured, clean work surface. Using a rolling pin, or a wine bottle, start in the middle and roll out into a circle large enough so you have some overhang. Place in your favorite deep pie dish.
Spoon the filling into the prepared pie crust. You may or may not have some of the thickened juice left over depending on how deep your pie dish is.
Grab the second wheel and roll out. Use a rolling pin or a bottle of wine or a glass. Once you’ve rolled it out, cut it into ¾ inch strips. Lay the first two strips down making an X. Alternate laying down horizontal and vertical strips, weaving them in an over-and-under pattern. Use your shortest strips for the edges of the lattice. Trim the edges and crimp the ends of the strips together with the bottom crust.
Mix the oat milk and agave and brush this over the edges and lattice and sprinkle with coarse sugar, if desired.
Bake 40-45 minutes or until the top is golden brown. Cool completely before serving.
