Place 2 sage leaves on top of each halibut fillet. Season with salt and pepper; wrap 2 slices of prosciutto around each fillet. Heat oil in a large skillet over medium-high heat; add fish. Cook 2-3 min., turning once. Add Marsala and stock to the pan; reduce heat and simmer, loosely covered, until fish is cooked through and flakes easily with a fork. Move fish to a warm serving platter. Whisk vinegar into pan; season sauce to taste and drizzle over fish.

Recipe courtesy of Consorzio del Prosciutto di Parma. Selection and availability of ingredients vary my market.