Trim the livers of connective tissue and fat. Rinse in a cold water bath that has been augmented with the vinegar. Drain and pat dry. Slice into 1/2-inch thick slices, and dredge lightly with the flour.

In a large, heavy-bottomed skillet, heat the olive oil over high heat until smoking. Add the liver pieces and sear until crisp and golden brown and medium rare inside, about 1 minute per side and remove to a plate. Be careful here as an extra minute in the pan can reduce your livers to liquid. Add the onion rings and cook over medium-high heat until they are softened and browned. Add the figs and the wines and cook over high heat scraping the bottom of the pan with a wooden spoon to dislodge any browned bits until reduced by half. Add the butter. Return the livers briefly to the pan to heat through, season sauce with salt and pepper, grated lemon zest, and parsley, and serve immediately.