Seared Steak with Braised Leeks and Chard

Sprinkle steaks with 1/4 teaspoon salt and pepper. Heat a large skillet over medium-high heat. Coat pan with cooking spray. Add steaks to pan; cook 4 minutes on each side or until desired degree of doneness. Remove steaks from pan. Add butter and mustard seeds to pan. When mustard seeds begin to pop, add leek to pan; cook 2 minutes, stirring occasionally. Add wine; cook 1 minute or until liquid evaporates, stirring constantly. Add stock and Worcestershire sauce to pan; cook 4 minutes or until leek is tender. Add remaining 1/8 teaspoon salt and chard; cook 2 minutes or until chard is wilted, stirring occasionally. Serve chard mixture with the steaks.