Combine 1/4 cup flour, water, and juice stirring with a whisk until well blended to form a slurry.
Combine ¾ cup flour, sugar, and salt in a large bowl. Cut in shortening with a pastry blender until mixture resembles coarse meal. Add slurry and mix until moist.
Roll out dough in between heavy duty plastic wrap into 12 inch circle and freeze for 10 minutes.
Preheat oven to 325 °F. Press dough into pie plate and shape edges if desired. Sprinkle all chopped dates, pecans, and walnuts into the bottom of pie dough.
In a large bowl, beat together all remaining ingredients. Pour mixture into pie crust, on top of chopped dates and nuts.
Place pie shield or aluminum foil around edges and bake in oven for 50 minutes. Remove pie shield or aluminium foil and continue baking for another five minutes.
Remove from oven and let completely cool. Serve warm or cold with whipping cream or ice cream.