1 beef flank steak (1-1/2 pounds)
1/2 cup water
1/4 cup red wine vinegar
2 tablespoons canola oil
1 tablespoon tomato paste
1-1/2 teaspoons garlic salt, divided
1 teaspoon dried thyme, divided
1/2 teaspoon pepper, divided
1 bay leaf
Whisk the water, vinegar, oil, tomato paste, 1 teaspoon garlic salt, 1/2 teaspoon thyme and 1/4 teaspoon pepper; in a small bowl, then add bay leaf. Pour into a large resealable plastic bag.
Score the surface of the steak, making diamond shapes 1/4 in. deep; add to marinade. Seal bag and turn to coat; refrigerate for 3 hours or overnight, turning occasionally.
Drain and discard marinade. Pat steak dry with paper towels. Combine the remaining garlic salt, thyme and pepper; rub over both sides of steak.
Using long-handled tongs, moisten a paper towel with cooking oil and lightly coat the grill rack.
Over medium-hot heat,on the grill (lid down), or broil 4 in. from the grill for 6-8 minutes on each side or until a meat thermometer reaches desired doneness Let stand for 5 minutes. Thinly slice across the grain. Be sure to slice across the grain, otherwise meat will be tough.