Preheat oven to 425. Line pie pan with plain pastry.
Peel, remove core and slice apples. Place in pie shell. Combine sugar, salt and nutmeg. Sprinkle over apples. Dot with butter. Bake at 425 degrees for 30 minutes, or until crust is brown and the apples are tender
Remove from oven. Cover the apples with halved marshmallows. Brown in slow oven 325. Serve warm.