Pastry:
Sift flour and salt together in bowl.
Cut in shortening until mealy.
Beat egg and lemon juice together slightly and stir into flour mixture with a fork until it holds together.
Gather pastry together into 2 balls, wrap in waxed paper and chill while filling is being prepared.


Filling:
Pare, core and slice apples.
They should measure 3 cups sliced.
Mix granulated sugar, flour, cinnamon, nutmeg, salt and sliced apples. 

To Assemble:
Bottom Layer:
Pour melted butter over bottom of a 9 inch pie pan.
Place walnuts, flat side up in pan, sprinkle brown sugar over nuts.
Next Layer:
Roll 1 pastry ball into thin circle about 11 inches in diameter.
Prick with fork lines and place on top of sugar and nuts.
Next Layer:
Cover with apple mixture.
Top Layer:
Now roll the second ball of pastry in a 10 inch circle and arrange on top of apples.
Crimp pastry edges to seal pie.
Prick top to allow steam to escape and bake [at normal pie baking temp*] 30 to 35 minutes or until nicely browned.

Cool in pan for 5 minutes, then invert onto serving plate and remove pan.
Serve warm.

*From Copilot:
"To bake a delicious apple pie, the recommended temperature is 425°F (220°C). At this temperature, the crust becomes golden and flaky while the apples cook thoroughly. The baking time typically ranges from 45 to 55 minutes, depending on factors like the type of apples used and your oven's efficiency.
If you're aiming for a slightly different texture, you can bake at 350°F (175°C) for 40 to 50 minutes for a tender filling and golden crust, or at 375°F (190°C) for 30 to 40 minutes for a crispier crust."