In a small bowl, combine the first seven ingredients. Pour 2/3 cup marinade into a large resealable plastic bag; add the beef. seal bag and turn to coat; refrigerate for 4 hours. Cover and refrigerate remaining marinade for basting.
Drain and discard marinade from beef. On four metal or soaked wooden skewers, alternately thread the beef, zucchini and mushrooms. Spoon over uncooked kabobs with reserved marinade; sprinkle with salt. Broil 4 in. from heat for 5 minutes on each side or until meat reaches desired doneness, basting frequently with reserved marinade. Place a tomato on each skewer before serving. Yield: 4 servings.