sheet apple pie

6-8 Granny Smith apples, sliced thinly
2 T flour
1/2-c brown sugar
1/2-c sugar
salt
1/2 t cinnamon
1/4 t nutmeg
1/2 c walnuts (optional)
butter

Mix dry ingredients, pour over apples, and toss.
Roll out pastry to cover the bottom of a sheet pan; pour apple mixture on top and dot with butter. Top with second pastry, brush with egg yolk, then cinnamon, then sugar.

Bake at 350 for 50 minutes.