Delia Smith's Liver and Bacon Casserole is made with lambs’ liver, butter, sunflower oil, plain flour, onion, streaky bacon, beef stock cube, just-boiled water, tomato ketchup, salt, and freshly ground black pepper. This hearty Liver and Bacon Casserole recipe creates a delicious dinner that takes about 30 minutes to prepare and can serve up to 4 people.