Cook onions in 1 tablespoon hot fat until golden brown; remove. Cut away membranes and large tubes from liver. Dredge with flour, salt and pepper, mixed together. Fry in remaining 2 tablespoons hot fat until browned on both sides. Add onions and water; cover and simmer for 1/2 hour or until liver is tender. Add more water, if necessary, to prevent sticking. 

Smothered Liver & Onions 2

1 1/2 pound of thinly sliced calf liver
3 onions, thinly sliced
1/2 cup of flour
Salt, pepper, and garlic powder
1/2 cup of cooking oil
1 cup of water

Season liver and roll in flour which has been lightly seasoned. Heat oil in heavy skillet. Brown liver on both sides. Add onions and simmer in covered skillet over low heat. Gradually add small amount of water. After 10 minutes, add more water. After another 10 minutes, add remainder of water. Cook until gravy thickens. Salt to taste; stir often.