Sprinkle liver with salt and pepper; dredge in flour. Set aside.
Sauté onions in hot bacon drippings in a large skillet until tender. Remove onions, reserving bacon drippings in skillet.
Cook liver in drippings over medium heat until browned on both sides; top with onion slices. Add water. Cover; simmer 20 minutes or until liver is no longer pink.
Transfer liver and onion slices to a warm serving platter; pour pan liquid over top. Serve immediately.