Comal

A comal is a cooking utensil used primarily for heating tortillas.  To use, the comal is placed over a heat source which may be an open fire or gas burner.  Once heated, the tortilla is placed on the top of the comal then turned so that it browns on both sides.

Clay Comal
This is truly the traditional comal which dates back to the Aztecs.  It is a large, slightly concaved disk of made of clay.  The comal may or may not be glazed. A seasoning process is suggested before using a clay comal.   One method of seasoning is to soak the comal in milk, then let it dry. The enzymes in the milk create a protective coating.  This comal does need to be handled with care as they can break if dropped or hit against a hard surface.

Steel Comal
In Mexico steel comals are inexpensive and common. They are prone to rust so they have to oiled repeatedly.  Aside from that, they function in the same way as the clay comal.  They get very hot so they do a good job browning tortillas.

Cast Iron Comal
The cast iron comal works very well because it provides nice even heat distribution.  It is sturdier than the steel comal but again, they all provide the same function.  Many of the cast iron comals from Mexico and Colombia have a coating that inhibits (but does not stop 100%) rust.  They still require a coating of oil after use.