In a large, heavy frying pan, combine pork with cold water and heat to boiling point. It should be slightly soupy.
Add onion, celery, pepper, bay leaf, savory, rosemary, nutmeg and cinnamon. Cook, covered, over medium-low heat for 1 1/4 hours; stir often. Add more water if mixture dries out.
Halfway through cooking time, season with salt to taste.
Stir in rolled oats and cook, stirring, for 1 to 2 minutes. Remove bay leaf and allow to cool. Setting the entire pot in the snow bank speeds up this process!
Meanwhile, line two 9-inch pie plates with pastry. When meat mixture is lukewarm, divide it between two pie shells and spread it out evenly.
Brush around outer edge of pastry with the beaten egg. Place top crust on the tart and press gently around the edge to seal. Trim pastry, crimp edges and cut steam vents in top crust. Decorate as desired.
Bake in preheated 425°F oven for 15 minutes, then reduce heat to 375°F and bake another 25 minutes or until crust is golden.