My mother cooked pigs liver, and sometimes ox liver, in the oven wth onions after soaking it in milk. Offal of any kind was the one thing I couldn’t get my children to eat. I buy lambs liver - sometimes calves if I can get it (it used to be a hell of a lot cheaper than if is now!), flash fried in a pan and served with onion gravy, mash and greens. I quite liked tripe as a child until I found out where it came from?. Put me off henceforth.