Sprinkle both sides of steak with salt and 1 Tbsp. pepper; brush with olive oil. Place grill pan over medium-high heat until hot. Cook steak in hot grill pan 5 to 7 minutes on each side or until desired degree of doneness. Transfer steak to a carving board, and let stand 5 minutes.
Meanwhile, combine pesto, chopped roasted red pepper, and lemon juice in a small bowl.
Cut steak into thin slices, and transfer to a serving platter. Serve with red pepper pesto.