DO-AHEAD TIP: Marinate steaks overnight or for at least 4 hours (see recipe).
Place steaks in a large zipper-topped plastic bag.
In a medium bowl, combine remaining ingredients (black pepper through vinegar). Blend until smooth then pour over steaks. Seal bag and turn to coat, making sure steaks are saturated with marinade. Refrigerate overnight or for at least 4 hours, turning occasionally.
At time of cooking, preheat grill to MEDIUM-HIGH. Grill steaks for 4 to 6 minutes per side or until cooked to desired level of doneness.
Serve and enjoy!