In a large sauté pan cook the fat and the onions over medium low heat until the onions begin to brown, about 15 minutes. Do not rush this step; you want the onions well cooked.
Add 1 teaspoon salt, ½ teaspoon pepper, and 1 teaspoon of whatever seasoning or dried herbs you are using. Cook for 30 seconds.
Combine ¼ cup of stock with the starch and stir well. Add the remaining stock to the pan, raise the heat, and bring to a boil.
Stir in the starch and stock mixture and cook, stirring, until thickened, about 1 minute. If using brandy or wine, stir it in now.
Add a few dashes of Worcestershire sauce if desired.
Taste the gravy and adjust the seasoning by adding more salt, pepper, seasoning, or herbs to taste. The gravy should be well seasoned.