You need enough pie crust for two two-crust pies. You can buy ready-made pie crust, but it is really not that hard to make. I make my own. Then you cut up about half of a rutabaga, two medium-large potatoes, and a medium onion into cubes. Mix all in a bowl. You also need to have handy, a pound of ground beef. Purists use roughly ground "chili" beef. All ingredients are obviously raw.
Roll out 1/4 of pie crust and alternately place chunks of ground beef and vegetables in a mound, as shown. Then you pull the far side over to cover everything and crimp the edges.
OK, I admit that this really looks messy, but no matter, you can eat the messy ones first. Don't forget to poke some steam holes in the middle.
Bake at 350 degrees F for about 30-40 minutes until they look done and a knife can be inserted easily in the middle.
You can eat as soon as done, or let cool a bit and then wrap in foil and put in plastic bag and freeze. When you are ready to eat one, take it out and let it thaw a bit. You can put it in an oven for 20 minutes or so, or microwave them. The oven method gives you a better crust, but I really don't care because I mostly like the filling.
Pasties are a very old food, eaten as far back as the 13th Century in England. Samuel Pepys used to write about them in his famous diary in the1650s. Here is some history: http://www.historic-uk.com/CultureUK/The-Cornish-Pasty/