The cheesy Tex-Mex dip made from melted cheese and chiles is called queso. Its fuller name is chile con queso, meaning “chile with cheese” in Spanish.
Queso is typically served warm as an appetizer or side dish, often with tortilla chips. Tex-Mex versions commonly use a smooth-melting cheese such as American cheese, processed cheese, Velveeta, Monterey Jack, or cream cheese, along with green chiles. Restaurants may add onions, tomatoes, pico de gallo, black beans, or seasoned ground meat.
The dish belongs to the twentieth-century Tex-Mex and Southwestern food traditions and is probably related to queso flameado, a northern Mexican dish associated with Chihuahua. Although “queso” simply means cheese in Spanish, U.S. restaurant menus often use the shortened word to mean this specific creamy dip. Pico de gallo, guacamole, and salsa may accompany queso or be mixed into it, but none is the melted cheese-and-chile dip itself. Queso can also be spooned over tacos, enchiladas, fajitas, and other Tex-Mex dishes.