Ideally, you'd start your gravy with some broth, or roast drippings, to bring the flavor. If you don't have those or don't ...
There is nothing better ... different than other gravy because it has hard-boiled eggs. Serve alongside your Thanksgiving turkey for a tasty gravy. "Another Thanksgiving recipe." ...
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 ...