Gravy mistakes happen! Here’s how to fix them. Too thick: Stir in a little stock to thin out the gravy. Remember that gravy thickens as it cools but it will loosen when you reheat it. Too thin: Mix 1 tablespoon each softened butter and flour to form a paste, then stir into the gravy and simmer for a few minutes to thicken. Too salty: Add unsalted broth, stock or even water to dilute the saltiness. Thicken the gravy again, if necessary (see above). Too greasy: Let the gravy cool, then skim off any fat that rises to the top. Reheat and whisk in any remaining fat. Too lumpy: Strain the gravy through a fine-mesh sieve.