Gluten-Free Blueberry Pie with Cornmeal Crust

Ingredients

• 1 cup rice flour white
• 0.5 cup tapioca flour 
• 0.3 cup potato flour 
• 0.5 cup cornmeal 
• 2 tablespoons sugar 
• 1 teaspoon xanthan gum 
• 0.5 teaspoon salt 
• 0.3 teaspoon pumpkin pie spice 
• 0.5 cup butter very cold cut into 1/2-inch pieces
• 0.3 cup shortening very cold cut into 1/2-inch pieces
• 0.3 cup water 
• 1.5 lb blueberries fresh
• 0.5 cup sugar 
• 0.3 cup cornstarch 
• 12 oz jam gluten-free
• 0.3 cup butter cut into small pieces
• 1 teaspoon lemon zest grated
• 1 tablespoon juice of lemon fresh
• 0.1 teaspoon salt 
• 1  eggs separated
• 1 tablespoon milk 
• 1 tablespoon sugar 

Equipment

• food processor
• bowl
• baking sheet
• baking paper
• oven
• knife
• wire rack
• plastic wrap
• aluminum foil

Directions

1. In food processor, place flours, cornmeal, 2 tablespoons sugar, the xanthan gum, 1/2 teaspoon salt and the pumpkin pie spice. Cover; pulse, using quick on-and-off motions, until blended.
2. Add 1/2 cup butter and the shortening. Cover; pulse until coarse crumbs form, about 5 seconds.
3. Add water; pulse just until dough comes together. Divide dough in half; flatten each into a disk. Wrap in plastic wrap; refrigerate until firm.
4. In large bowl, toss blueberries, 1/2 cup sugar, the cornstarch, preserves, 1/4 cup butter, lemon peel, lemon juice and 1/8 teaspoon salt; set aside.
5. Line cookie sheet with foil; place on lower oven rack to catch any drips.
6. Heat oven to 375°F. Unwrap 1 dough disk (keep remaining dough refrigerated until ready to use). Between 2 sheets of cooking parchment paper generously sprinkled with rice flour, roll dough into 12-inch round about 1/4 inch thick. Carefully peel off top piece of parchment paper; replace paper and turn round over. Peel off parchment paper from second side of dough and discard.
7. Place upside-down 9-inch glass pie plate on dough round. Turn plate with dough over; remove parchment paper and discard. Pat dough into plate, pressing together any cracks or tears. In small bowl, beat egg white.
8. Brush over dough. Spoon filling into crust-lined plate.
9. Unwrap second dough disk. Between 2 sheets of cooking parchment paper generously sprinkled with rice flour, roll dough into 12-inch round about 1/4 inch thick. Carefully peel off top piece of parchment paper; invert dough onto filling. Peel off parchment paper from second side of dough and discard. Using sharp knife, trim crusts even with edge of plate; crimp edge with fork to seal.
10. Cut vents in top crust. In small bowl, beat egg yolk and milk.
11. Brush over dough.
12. Sprinkle with 1 tablespoon sugar.
13. Bake 1 hour to 1 hour 10 minutes or until crust is golden and filling is bubbly. Cool completely on cooling rack, about 2 hours.