I was introduced to the idea of substituting black truffles for the traditional anchovies by James 'Animal' Nowak of Terra Fleurs, a wild food forager in Seattle. It is lighter on salt and has a wonderful, deep earthy flavor. THis is my recipe based on James' description.
If you can't forage for truffles yourself, or can't afford the high cost of buying them, consider substituting about a tablespoon of more affordable bottled truffle oil.