Boil potatoes and carrot until fork tender. Drain. Place in a large bowl.
Meanwhile, saute the onion and cabbage until the onion is translucent and the cabbage has cooked down. Stir into the potato/carrots and spices. Cool to about room temperature.
When you are ready to go, stir in your cold, leftover corned beef. You should have about 7 cups of filling.
Make the dough:
Place the butter and dry ingredients into a food processor. Add the vinegar and then water one tablespoon at a time and pulse just until the mixture sticks together. Place on lined baking sheets and bake for 60 minutes or until golden brown and cooked through.
Place on lined baking sheets and bake for 60 minutes or until golden brown and cooked through.
Fill with 3-4 tablespoons of the meat filling (centered).
Fold in half. Prick the top and crimp shut along the side with a fork.
Beat together the egg wash ingredients. Brush with egg wash.
Place on lined baking sheets and bake for 60 minutes or until browned and cooked through.
Notes
If you have any leftover filling, fry it up and make hash!