Au jus

Au jus () is a French culinary term meaning "with juice". It refers to meat dishes prepared or served together with a light gravy, or broth, made from the fluids secreted by the meat as it is cooked. In French cuisine, cooking "au jus" is a natural way to enhance the flavour of dishes, mainly chicken, veal, and lamb. In American cuisine, the term is mostly used to refer to a light sauce for beef recipes, which may be served with the food or placed on the side for dipping.
Ingredients and preparation.
In order to prepare a natural "jus", the cook may simply skim off the fat from the juices left after cooking and bring the remaining meat stock and water to a boil. "Jus" can be frozen for six months or longer, but the flavor may suffer after this time.
"Au jus" recipes in the United States often use soy sauce, Worcestershire sauce, salt, pepper, white or brown sugar, garlic, beets, carrots, onions, or other ingredients to make something more like a gravy. The American "jus" is sometimes prepared separately, rather than being produced naturally by the food being cooked. An example could be a beef "jus" made by reducing beef stock to a concentrated form, (also known as "Glace de Viande") to accompany a meat dish. It is typically served with the French dip sandwich.
"Jus" can also be made by extracting the juice from the original meat and combining it with another liquid e.g. red wine (thus forming a red wine "jus").
A powdered product described as "jus" is also sold, and is rubbed into the meat before cooking or added afterwards. Powdered forms generally use a combination of salt, dried onion, and sometimes sugar as primary flavoring agents.
Use as noun.
In the United States, the phrase "au jus" is often used as a noun, owing to it having been corrupted in culinary references into the noun form: rather than a "sandwich au jus", the menu may read "sandwich with au jus".