A roughly authentic home-made recipe consists of the following:

2 medium-sized fish, whole, roughly 3 lbs. worth; the fattier the better (i use white sea bass)
3 cups sea salt
1/4 cup red wine vinegar
1/4 cup olive oil
2 cups must (unfermented grape wine)(optional)
1 cup Italianbasil, chopped
2 tbs. cumin
Other herbs, to taste

Take the fish and filet the meat off the bones; you may want to remove the liver and bladder, but leave the rest of the organs. In an hermetically sealable glass jar, stamp the herbs into a layer on the bottom. Next, add a layer of the fish, topped by a layer of the salt between one and two fingers deep; continue alternate layers until you run out of fish. Seal the jar, and leave outside in the heat, stirring or shaking every few days. After two to three weeks, bring it in, and boil it down to about 2/3. Finally, strain it through a cheese cloth to remove any remaining solids. Enjoy.