In a cast iron skillet, or frying pan, melt butter. Add the onions to the melted butter, and cook to a carmel color. Add salt and pepper to flour to bread chicken livers. Add liver to melted butter and onions, turn often to brown. Continue cooking over medium low heat for about 30 minutes. Serve with long grain rice, and a green vegetable like asparagus, or spinach,green beans, etc.