The Mexican dish of a tortilla filled with cheese and cooked on a griddle is a quesadilla.
A traditional quesadilla is made by warming a corn tortilla on a comal, adding cheese and sometimes other fillings, folding it in half, and heating it until the cheese melts. Oaxaca cheese is a classic filling in many parts of Mexico, while meats, chorizo, potatoes, squash blossoms, huitlacoche, onions, and peppers are also common.
The dish has roots in colonial Mexico and has developed into many regional forms. Corn tortillas are especially common in central and southern Mexico; flour tortillas are more associated with northern Mexico. Quesadillas fritas are folded and fried until crisp rather than simply cooked on a dry griddle.
One famous regional difference concerns Mexico City: there, a quesadilla may not automatically include cheese, so diners sometimes have to request it. Outside Mexico, especially in the United States, quesadillas are often made with two flour tortillas and a broad range of fillings.