We all agree that the best au jus is made from pan drippings. But this easy au jus recipe is a great substitute when you have no drippings.
Add the oil to a saucepan, and onions, and cook to caramelize (about 5 -10 minutes).
Add garlic and cook for an additional minute.
Deglaze the pan with Vermouth.
Add Worcestershire sauce and cook for another minute, stirring so it doesn't stick.
Add the beef broth and bring to a light boil, reduce heat, and simmer about 3 minutes.
Create a slurry by mixing the flour and water in a small bowl until smooth. Whisk into the pan and simmer for a few minutes.
I leave mine chunky, but if you prefer a smooth au jus, strain the broth and return it to the pan prior to adding the slurry.
Make ahead of time and refrigerate up to a week.
Freeze it and it will last for six or more months. Keep in mind that while it will keep even longer, the flavor will fade over time.