Boil 1/2 pot of salted water w/ 1/2 onion, drop in the water gizzards and let them boil for 20 minutes, keep the lid halfway closed, and be close by because water will start to bubble. Boil on high for first 5 minutes, then turn down the heat to lower temperature. It doesn't have to be simmer, just to keep boiling.
Serve it over POLENTA (RECIPE HERE), RICE OR ON IT'S OWN.
When you sauteing gizzards, they tend to burst from time to time, if you have fitted saute pan lid that would be the best to keep you protected! You can also make soup/stew base with gizzards just add salt to taste, onion, celery, bay leaf, and carrots. After boiling, just take out gizzards for sauteing and drain the stock into container separating it from veggies. FOR ME IT IS VERY IMPORTANT TO boil gizzards before sauteing. They are still chewy and get that softer bite. Sometimes I boil them even longer than 30 minutes.