MARINADE: Combine ingredients and pour over steaks.
Cover with plastic wrap. Refrigerate for 1 to 24 hours.
MUSHROOMS: Heat oil in large skillet over medium-high heat. Add mushrooms and shallots; cook until onion is softened, about 4 minutes. Add garlic and sauté for 30 seconds. Stir in thyme, wine and Worcestershire sauce; cook, stirring often for 2 to 3 minutes or until wine is reduced. Season with salt and pepper to taste. Serve over barbecued steak.
TIP: You can stir in 1/4 cup of sour cream into the Sautéed Mushrooms for a stroganoff-style sauce if you like.