Adding chicken-flavored Better Than Bouillon is a slam-dunk (or there's ... which enriches the sauce and helps emulsify it.
But if your gravy still seems to lack sufficient flavor, a bit of bouillon will amplify its meatiness. hand holding jar of roasted chicken bullion paste, brand better than bullion ...
Kook recommends using high-quality bouillon paste rather than the powder ... preparing your gravy from the leftover fats and juices, add a bit of the bouillon paste. Using chicken and beef ...