Place the beef broth in a medium saucepan over medium-high heat and bring to a boil.
Add the onion powder and garlic powder (and Worcestershire sauce if desired).
Mix the cornstarch and cold water together in a small bowl until there are no lumps in the mixture.
Add the cornstarch mixture to the boiling beef broth and simmer on medium-low heat. Keep stirring until thickened.
Add salt and pepper to taste. Add zaatar and let it simmer for 5 minutes so that all the flavors infuse into the gravy.
Serve with your favorite meat, vegetable, or potato dish.