• Combine marinade. In a small bowl, whisk 1/4 cup olive oil, 1/4 cup balsamic vinegar, 1/4 cup soy sauce, 2 Tablespoons Worcestershire sauce, and 1 Tablespoon garlic until combined.
• Marinate steak. In a bowl or a zip-top bag, place 1 1/2 pound steak and pour the marinade over the top. Seal bowl or bag and place the steak in the refrigerator. Marinate at least 30 minutes, but giving it 4 hours or more will only improve the flavor.

Grill a steak

• Preheat grill to medium high heat. Clean the grill grates with a wire brush and lightly oil the grates. Place the steak onto the grill and cook 4 to 5 minutes, or until browned. Turn the steaks over and grill another 4 to 5 minutes for medium-rare (135° F): 5 to 7 minutes for medium (140° F); or 8 to 10 minutes for medium-well done (160° F).
• Rest steak. Remove steak from the grill and tent with foil. Let rest 5 minutes before serving. Slice meat against the grain. Top with a slice of butter and chopped parsley, if desired. Salt and pepper, to taste.