Two common versions of meat are used in gyro sandwiches. In Greece, the filling is typically made with pork. Thin slices of the meat are stacked onto a spit, where they compress under their own weight. As the outer edges cook and brown, they're shaved away to fill sandwiches, leaving a fresh layer of pork exposed to the rotisserie's heat. Greek-American versions are made with ground meat, usually a mixture of beef and lamb, though pure-lamb gyros are sometimes available. The meat is formed into a sausage-like loaf, then cooked on a vertical rotisserie in the same way.

The rotisserie used in gyro shops is a special variety that holds the meat vertically as it's cooked. One to three heating elements are banked around and behind the meat, leaving the front and most of the sides free for slicing. The rotisseries on home grills and ovens -- even countertop ovens -- are invariably horizontal. They can still produce a satisfactory result, but it takes some extra work.

To make the sliced meat version of gyros meat, select a roast of pork or lamb with a diameter wider than the prongs on your rotisserie. Use a long, sharp knife to carve the meat into slices 1/8th inch or less, or ask your butcher to slice it for you. It's easiest if the meat is slightly frozen, which makes it firmer. Season the slices with salt and pepper, and herbs such as oregano, if you wish. Slide the slices onto your rotisserie's spit and secondary prongs, pressing them together as tightly as possible. Roast the meat at 400 degrees Fahrenheit or higher, periodically stopping the rotisserie and slicing away the meat from the outside. You might need to remove the spit assembly to do this.

Ground meat gyros are made in much the same way as sausage, so it helps if you read a good sausage-making guide before you attempt the procedure. Whether you use lamb or a beef-lamb mixture, the meat should be finely ground, lightly salted and thoroughly chilled. Process the meat to a smooth paste in your food processor or stand mixer, adding ice water or crushed ice as directed in your recipe. Form the meat into a log shape, wrap it in parchment paper, and then in foil. Wrap the entire log in heavy-duty plastic wrap, then poach it in 180 F water until its internal temperature reaches 160 F. Let the log cool, then transfer it to your rotisserie's spit. Slice away the outer layers as they brown, and use them to make your gyros.