In a shallow bowl soak liver in milk to cover for at least 2 hours; remove, discard milk and pat dry.
Dredge liver in seasoned flour, shaking off excess. Heat oil in a saute pan, add liver and sear first side until well-browned, about 3 minutes. Turn and sear second side 30 seconds for medium-rare; cook a little longer for medium. Remove to a plate and keep warm. To pan add 1 tablespoon of butter. Add shallots and pear; toss and cook 2 minutes. Add vinegar and cook for 1 minute. Add stock, bring to a boil and begin to reduce. Return liver to pan, taste sauce for seasoning and add remaining butter. Serve liver and sauce with polenta, if desired.
Yield: 2 to 3 servings