Grandma's Strawberry-Rhubarb Pie

INGREDIENTS

• 3 tablespoons butter, cubed small
• 1/4 cup salted butter
• 1/2 teaspoon lemon juice
• Pinch salt
• 2 cups all-purpose flour, plus additional flour as needed, up to 1/4 cup
• 1 tablespoon all-purpose flour
• 2 teaspoons vinegar
• 3 teaspoons sifted powdered sugar
• 1/2 cup cake flour (recommended: Soft As Silk)
• 2 1/2 cups chopped red rhubarb, fresh
• 1/2 teaspoon lemon zest
• Large granule sugar
• 1 teaspoon vanilla extract
• 1/2 cup butter-flavored shortening (recommended: Crisco)
• 1 egg
• 2 tablespoons minute tapioca
• 1/2 teaspoon ground cinnamon
• 1/4 cup ice cold water
• 1 1/2 cups sugar (1 1/4 cups for high altitude)
• 1 egg white beaten with 1 teaspoon water
• 2 1/2 cups de-stemmed, washed and cut strawberries (in larger pieces)