1. Add balsamic vinegar, olive oil, shallots, and rosemary to a blender and blend until smooth.
2. Pour marinade in a resealable bag or bowl. Add steaks and coat. Refrigerate at least six hours.
3. Preheat grill to medium-high heat.
4. Remove steak from marinade; discard leftover marinade. Season all sides of steaks with salt and pepper.
5. In a small bowl, whisk dressing ingredients together and set aside.
6. Cut romaine hearts in half, lengthwise, and brush all sides with olive oil. Season with salt and pepper.
7. Place steaks and romaine hearts on grill, cut side down. Grill for five to seven minutes.
8. Flip steaks and romaine hearts and grill for an additional five to seven minutes until steaks have reached an internal temperature of 145ºF, or your desired doneness.
9. Remove steaks and romaine hearts from grill. Allow steaks to rest three to four minutes before serving.
10. Serve romaine hearts whole drizzled with the dressing mix. Enjoy!