Beef Filets With Portobello Sauce

Place a large skillet coated with cooking spray over medium-high heat; brown steaks on both sides. Remove from pan., Add mushrooms and wine to pan; bring to a boil over medium heat, stirring to loosen browned bits from pan. Cook until liquid is reduced by half, 2-3 minutes. Mix flour and broth until smooth; stir into pan. Stir in all remaining ingredients except chives; bring to a boil., Return steaks to pan; cook, uncovered, until meat reaches desired doneness (for medium-rare, a thermometer should read 135°; medium, 140°), 1-2 minutes per side. If desired, sprinkle with chives.