I remember my mother and her friend making this when I was young. It's so yummy and it's a perfect dessert for Autumn when fresh sweet potatoes are plentiful in Alabama. I was raised on a farm and we used to dig potatoes and store them in the storm pit to keep them from becoming rotten. I think you'll like it, It's also a good Thanksgiving desert. I wish I had one ready to eat right now !!
In a saucepan, cook sweet potatoes in water until tender, about 10 minutes. Drain, reserving 1 1/2 cups of cooking liquid. Layer potatoes in a greased 13 inch x 9 inch baking dish; add reserved liquid. Combine sugar, flour, cinnamon, nutmeg and salt; sprinkle over potatoes. Dot with butter.
For pastry, combine flour and salt. Cut in shortening until mixture resembles coarse crumbs. Gradually add in water, toss with a fork until a ball forms. On a floured surface, roll pastry into a 13 in x 9 in rectangle. Place over sweet potato filling; cut slits in top. Brush with butter; sprinkle with sugar.
Bake at 400 degrees for 30-35 minutes or until top is golden brown. Spoon into dishes; serve hot with a scoop of whipped cream on top sprinkled lightly with nutmeg. Yum, Yum