Filling aside, the torta is as standardized a sandwich form as you'll find. At the Chicago taquerias I've frequented, the formula is constant: the bread will be toasted bolillo or telera with a smear of refried beans; the vegetation will be comprised of lettuce, tomato, and sliced avocado; each bite will feature a gentle tug from barely-melted shredded white cheese; and greatness will be judged based on the use of runny crema or cloying sour cream. As long as the filling is properly cooked and seasoned, the experience is rather homogeneous every time.
Still, given the right filling, the torta is capable of surprises. The Milanesa de Res Torta ($5.25) from Taqueria Los Comales in Logan Square is designed to address an issue with the common filling that I didn't even know existed. Unless cooked perfectly, our waitress explained, breaded steak has a tendency to fight back when you bite into it. Los Comales' solution for getting around tough, rubbery steak that leaves the rest of the sandwich behind is to run the beef (with a little pork thrown in for extra rich flavor) through a meat grinder. The ground meat is then flattened into thin disks, breaded, and cooked in fat on the griddle until crisp all over. The flavor and texture is gyros meets sausage meets smash burger meets breaded pork tenderloin meets schnitzel. Combined with the familiar torta garnishments, this fried sandwich was a genuine surprise, and one to seek out when you find yourself ho-humming the everyday torta.