In a large frying pan, cook chicken livers and onions in 1/4 cup butter over medium heat, turning and stirring livers until lightly browned, about 10 minutes. Transfer chicken liver mixture to a food processor. Add cooked chicken and seasonings. Process until mixture is pureed. Cut remaining 1/2 cup butter into pieces. Add to chicken liver mixture. Process until fluffy. Spread chicken liver mixture in a mold or crock. Cover and chill several hours or overnight to blend flavors. Makes 3 cups.