Since lots of people are too impatient to click on links, here are some interesting tidbits from this Wikipedia entry:
A pasty (pron.:/ˈpæsti/, Cornish: Hogen; Pasti, also ‘Pass-tee), (sometimes known as a pastie or British pasty in the United States) is a baked pastry a traditional variety of which is particularly associated with Cornwall in Great Britain. It is made by placing uncooked filling typically of meat and vegetables, without meat in vegetarian versions, on a flat pastry circle and folding it to wrap the filling, crimping the edge to form a seal. After baking, the result is a raised semicircular end-product.
The term “pasty” is an English word borrowed from Medieval French (O.Fr. paste from V.Lat pasta) for a pie, filled with venison, salmon or other meat, vegetables or cheese, baked without a dish. In 1393, Le Menagier De Paris contains recipes for pasté with venison, veal, beef, or mutton.
Migrating Cornish miners helped to spread pasties into the rest of the world during the 19th century, says the Wikipedia entry. Most countries that adopted the food were English-speaking.
The Mexican state of Hidalgo, and the twin silver mining cities of Pachuca and Real del Monte (Mineral del Monte), have notable Cornish influences from the Cornish miners who settled there with pasties being considered typical local cuisine. In Mexican Spanish, they are referred to as pastes.