Heat a large skillet over medium-low heat and add 5 tablespoon of the cooking fat and the sliced onions. Cook slowly, stirring often, for about 20 to 25 minutes, until the onions are really soft and caramelized.
6 tablespoon cooking fat, 5 large onions
Near the end of the cooking process of the onions, heat another pan over a medium-high heat and cook the liver with the rest of the cooking fat, about 3 minutes on each side.
4 large slices pork or beef liver, 6 tablespoon cooking fat, Salt and pepper to taste
Serve the liver topped with the delicious and creamy cooked onions. This is also delicious served with some homemade salsa on the side.