1. Heat a large skillet over medium-high heat. Sprinkle both sides of steak with salt and pepper. Coat pan with cooking spray. Add steak to pan; cook 5 minutes on each side or until desired degree of doneness. Place steak on a cutting board; let stand 5 minutes. Cut steak diagonally across grain into thin slices.
2. While steak cooks, combine sour cream and next 5 ingredients (through juice) in a small bowl, stirring with a whisk. Stir in chives and parsley. Serve sour cream mixture with steak.