In Catholic Traditions In The Home And Classroom, author Ann Ball mentions that "legend reports that he had to endure severe temptations and that the devil often appeared to him in the form of a pig. Thus, pork is the traditional fare of the dinner on St. Anthony's feast day."
Cooking With the Saints offers a recipe for Olla De San Anton (St. Anthony's Stew) which they say is very popular over in Spain, and attempts "to use as much as possible of the fresh pork." Even though the author has updated the recipe by "eliminating some of the more exotic pork cuts, such as ear or tail" it still contains pork belly and blood sausage, therefore you won't catch me making it. Personally I would be much more inclined to make Rachel Ray's Roasted Pork Tenderloin or Pork Skewers with Pineapple-Scallion Rice.
Another option would be to prepare some Monastic Soup or any other recipe From a Monastery Kitchen since St. Anthony was known as the "Father of Monks." Here is a simple recipe in honor of St. Anthony from the aforementioned book.
St. Antony of the Desert Soup