Take 2 large potatoes, peel and put them in whole into whatever you are making. The potatoes will absorb the salt.
It may be possible to "thin" the salt out by adding water or stock and then "re-thickening" with corn starch and water to restore consistency. A bit more seasoning (other than the salt) may be required....
Bon appétit!
You can also add some bread to absorb some of the liquid, remove bread and then add either red currant or cranberry jelly to the gravy this is both tart and sweet and works well in most brown stocks or gravies