What you will need:
1 (1 1/2- to 2-pound) flank steak
1/3 cup Patricia & Paul Espresso Balsamic Vinegar
1/3 cup Patricia & Paul Chipotle Olive Oil
3 TBS light brown sugar
2 garlic cloves, minced
2 tsp Worcestershire sauce
½ tsp cracked black pepper
Place steak in a large zip-top bag. In a medium measuring cup or a bowl with a spout, whisk together Balsamic, Olive Oil, brown sugar, garlic, Worcestershire and pepper until well blended. Pour mixture over steak flipping several times to coat. Carefully squeeze all of the air out of the bag and seal. Place the bag in a dish and marinate in the refrigerator for at least 4 hours or, preferably, overnight.
Remove steak from the marinade and discard leftover marinade. Allow steak to come to room temperature on the countertop for about 30 minutes. Preheat grill to medium and pat meat dry with a paper towel. Salt meat on both sides then grill for about 6 minutes per side until an instant-read thermometer shows 120 degrees for rare and 125 degrees for medium. Let the steak rest for 5 minutes and then slice thinly against the grain and serve.