Have you ever gone to season a dish and had the lid fall off and spill salt everywhere, ultimately ruining the meal you've work hard to create? I did this once when cooking lasagna, after I'd had the tomato sauce simmering for over 3 hours! I was just about to take the pan off the stove top and layer up my lasagna all ready to go in the oven and BANG, salt everywhere!
There is a way to fix this, even if you've just over seasoned and need to reduce the saltiness of the dish. Peel a potato, chop it into quarters or eighths and chuck it in raw. I don't know how it works, or why, but after further simmering, the sauce is usable and the potato can be discarded.