Make the stock and keep it warm on the stovetop.
Soak the mushrooms in the cup of warm water for about 10 minutes. Strain the water and set aside. Chop the mushrooms.
Clean the livers, removing any bits of bile or little filaments, and chop the liver into pieces of about 1 cm (½ in). Heat the olive oil in a large saucepan suitable for making risotto.
Add the onion and sa