Demi-glace Sauce

Demi-glace is a rich brown sauce traditionally made by combining equal parts of veal stock and Espagnole sauce. 

The mixture is then simmered and reduced by half.

You can also do variations of this sauce to complement other types of meats or vegetables by substituting beef, chicken, or vegetable stock for the veal. 

Wine added to these sauces change dramatically the flavor of the sauces and create the bridge of flavor to the wine.