Rinse livers; pat dry. In a large skillet cook livers, mushrooms, and onion in hot oil over medium-high heat about 5 minutes or till liver centers are only slightly pink and onion is tender. Drain; remove mixture from skillet.
In a bowl stir together sour cream or yogurt, water, flour, sherry or milk, and bouillon granules. Add to the skillet. Cook and stir till thickened and bubbly. Stir in chicken-liver mixture and bacon; heat through. Season to taste with salt and pepper. Serve atop hot fettuccine or rice. Sprinkle with parsley, if desired.