Calves liver is a lovely treat and full of precious iron. We like it with onion gravy! Try it as follows:

Melt 25gm of butter in a frying pan. Peel and finely chop 1 onion or two shallots. Cook gently until they are soft and lightly browned. Add about 50ml of sherry (and flambe if you are feeling adventurous). Add 500ml of beef stock (we like the Knorr Beef stock pots). Bring to the boil and then turn down the heat to let the stock reduce and thicken. This can take around 30 minutes. Add a knob of butter at the end.

In a separate pan add another 25gm of butter and let it melt over a medium heat. While the butter is melting, season the liver with salt and black pepper. Add the sliced liver to the pan and cook on one side for 1 to 2 minutes , flip over and cook the other side for 1 minute.