Trim steak of fat. Marinate in mixture of wine, vinegar, oil, rosemary and pepper, one hour, at room temperature, turning two or three times.

Heat barbecue. Remove steak from marinade and salt to taste. Grill steak over medium-high heat until done -- about 8 minutes on each side for medium. Let sit five minutes and cut into 1/4-inch-thick slices.

For sauce, slice mushrooms and sauté in the oil until tender. Add remaining ingredients to pan and reduce about 3 minutes. Serve hot with sliced steak.

This recipe yields 6 servings.