A dish called higado con vinagre by some in our Sephardic community.
Fry the breadcrumbs and crushed garlic in hot oil until they are slightly coloured, and the garlic becomes aromatic and sweet. Add vinegar, salt and pepper to taste, and sugar, and bring to the boil.
Poach the slices of liver in this mixture, simmering gently for 5 to 10 minutes, until just cooked. They must not be overdone.
Serve garnished with chopped parsley.