Oh, this can be improved upon. You should use shredded cabbage and chop up that seitan! And use a softer dough. (sorry.)
This is my mother's Runza recipe (including her favorite ingredient, 'spray butter', ha):
Brown 1- 1 1/2 pounds hamburger (or seitan!)
1 chopped onion
1 bag shredded cabbage
1/2 cup water
1/2 tsp salt, 1/4 tsp pepper
3 or 4 shakes of hot sauce
Cook until onions and cabbage look done
2 cups warm water (not too hot, it would kill yeast)
2 pkg. yeast (I use quick rise yeast)
1/2 cup sugar
1 1/2 tsp salt
1 stick margarine (melted and cooled)
6 1/2 cups flour
Mix water and yeast, sugar & salt & stir well until dissolved. Add egg & melted margarine. Stir in flour.
You can stir and kneed this until all the flour is mixed in instead of a big mixer.
Put in refrigerator for 1-2 hours.
Divide dough into 16 equal balls and roll each one into oblong shape. Fill with cooled hamburger/cabbage mixture.
Bake at 350* 15-20 minutes or until brown on top and bottom. Spray with spray butter. These freeze well in ziplocks.