This recipe for liver pate is based on Apicius 9.10.10. The original recipe is written as follows:
Salsum sine salso: iecur quoques, teres et mittes piper aut liquamen aut salem; addes oleum. iecur leporis aut hedi aut agni aut pulli, et si uolueris in formella piscem formabis. oleum uiridem supra adicies.
Salt fish without salt fish: cook liver, pound it and add pepper and either liquamen or salt. Add oil. Use hare’s or kid’s or lamb’s or chicken’s liver, and if you like you can shape it like a fish in a mould. Pour green oil over it.
Latin text and translation from Grocock, C. W., and Sally Grainger, eds. Apicius. Prospect Books, 2006, p. 294-295.
Apicius 7.10.2 tells us to soak the liver in milk prior to cooking it to get rid of the metallic taste of liver due to its high blood content. This is a common technique used nowadays as well. He says:
Aliter [iecinera] in pulmonibus: ex lacte lavas pulmones et colas quod capere possunt…
Liver and lung are also cooked in this way: soak well in milk, strain it off if offensive in taste.
Latin text and translation from Grocock and Grainger, Apicius, edition.