Liver is a nutrient-dense food containing high levels of iron, vitamin A and B, folate and more. Although many people don’t appreciate liver, others love it. To reduce the intensity of its flavour, you can soak it in vinegar for 30 minutes to a few hours before cooking. Pat dry before cooking.
I coat it with a bit of flour and lots of paprika (Hungarian semi-sharp paprika is particularly good in this). I sauté onions and mushrooms in olive oil until they are partially cooked, and then add the liver. It takes only a few minutes to cook. Just before I take it off the heat, I add a hearty splash of vinegar (red wine or balsamic).