In a skillet over medium heat melt butter with oil.
05Add steaks and cook to desired doneness (5-10 minutes per side). Transfer steaks to plates and cover with foil to keep warm.06Pour off fat from skillet.07Put skillet on high heat and stir in wine, scraping up browned bits. Boil for 3 minutes or unti it is syrupy.08Whisk in tomato paste. Remove from heat.09Whisk in remaining 2 tablespoons butter (1 piece at a time), incorporating in sauce.10Stir in prosciutto and parsley.11Spoon sauce over steaks.