Cut beef steak into 1 1/4-inch pieces. Combine marinade ingredients. Place beef and marinade in food-safe plastic bag; turn to coat. Close bag securely and marinate in refrigerator 6 hours or as long as overnight, turning occasionally.
Heat 2 tsp oil large nonstick skillet over medium heat until hot. Add mushrooms; cook and stir until tender. Remove and keep warm. Meanwhile cook rice according to package directions, omitting salt and butter. When rice is done, stir in mushrooms.
Soak eight 9-inch bamboo skewers in water 10 minutes; drain. Remove beef from marinade; discard marinade. Alternately thread beef, onion and squash evenly onto skewers. Place on grid over medium, ash-covered coals. Grill, uncovered, 8 to 10 minutes for medium rare to medium doneness, turning occasionally.
Serve kabobs over wild rice.
Servings: 4