Q: What is Gruyère cheese, and is there a substitute?

A: Gruyère is a firm cow's milk cheese with a rich, nutty flavor. It originated in the Swiss town of Gruyères but is also widely produced in France. Although it's a delicious eating cheese, Gruyère is often used for cooking; it's a classic fondue cheese because it melts so well.

For cooking and melting, seek out a high-quality aged cheese at a cheesemonger or specialty store. A cheese that has been aged melts better without curdling than the young cheeses generally available in supermarkets.

You can substitute other good Swiss cheeses for Gruyère, such as Emmantaler.