Mexico - Thinking the Mexican sandwich is limited to the widely known torta is like the medieval belief that the earth is flat. Not only is it dead wrong, there are whole other Dagwood worlds to explore out there.

Mexican sandwiches have expanded to all sorts of fillings and techniques that leave some of our proud American sandwiches trailing in the evolutionary chain. Here are five you should eat, and these are just the beginning.

The Torta

The torta is a popular Mexican sandwich which can be found at most any restaurant or street vendor in Mexico. The sandwich is built by slicing open an encased chorizo sausage (or your choice of meat), and emptying out the crumbled meat on the grill.

The cheese layer is grilled on its own, directly on the flat-top, a change from the typical, melted-in-sandwich style seen in American sandwiches. As the cheese and chorizo finish up, a buttered roll joins them over heat.

The roll gets a smearing of beans before being carefully stacked with the meat and cheese, as well as avocado, tomato, and lettuce. The torta is best enjoyed standing against the counter at a street vendors cart, watching the cook grill up the next torta, trying to ignore the finished sandwich so you don't try to force another down.

The Cemita

While the town of Puebla lays claim to the creation of the torta (also the Mexican traditional sauce molé and another national dish, chilies en nogada), its current sandwich loyalties lie with the cemita. At its most basic, the cemita is distinguished from a torta primarily by the eggy, sesame-seed speckled bun.

It's not hard to understand why this sandwich is a point of pride. This is a sandwich that will keep you full for days and cover pretty much all the food groups: fried meat (in the form of a breaded cutlet called "milanesa"), lunch meat (a thick layer of sliced ham), cheese (quesillo, the cheese that requires oh-so-many stringers), and of course the cemita-specific bread. There are even a few vegetables, if you count the avocado and a spicy slaw of pickled peppers and onion.

The Pelona

The fried roll sets the pelona apart from other sandwiches, creating a contrast between the cool, runny cream and the crunchy bread, still warm from the oil. Inside, shredded beef spills over a bed of lettuce and chopped avocado, doused in crema (the thin Mexican dairy product, vaguely related to sour cream), and your choice of red or green sauce.

The small-ish pelona is considered a snack on the way to bigger sandwiches, yet its fresh vegetables and fried shell of bun make it a worthy stop along the Mexican sandwich path.

Chanclas

A pair of sandwiches set afloat in a sea of chili sauce is not the easiest thing to eat while standing on the street, so it could be hard on your clothes. For chanclas, though, it's definitely worth it.

White bread is sliced and stuffed with shredded beef, avocados and onions. The slightly spicy and blindingly red sauce is ladled over the top of the pair — and they come only in pairs, like the flip-flops for which they're named. Yes, like huaraches, the oblong fried masa base chanclas are a member the elite club of Mexican foods named after sandals.

The Pambazo

The mighty pambazo, heavyweight of the Mexican sandwich world, picks up where the chanclas and the pelonas give up.

Named for the type of bread used, the pamabazo is dipped into a sauce (made from guajillo chiles), giving it the same flavor-sponge properties as the chancla, and then it's fried in oil, similar to the pelona.

With fillings that read like a college kid on a dining hall bender, it starts with either shredded beef or sliced ham, gets a little extra starch from a sprinkling of home-fry-like potatoes, a liberal smattering of cheese, a thick layer of refried beans, and a barely there, nearly symbolic addition of lettuce.

A messy assemblage of ingredients barely capable of holding themselves together, the pambazo is the far end of the sandwich evolutionary chain from the simple, neatly organized torta.