Lazy Man's Sirloin Kabobs

1 boneless beef top sirloin steak, cut 1-inch thick
1 (1 ounce) packet dry ranch salad dressing mix
2 tablespoons water
1 tablespoon vegetable oil
1 medium green or red bell pepper cut into 1-inch pieces
1 medium yellow squash or zucchini, halved lengthwise,
    sliced crosswise into 3/4-inch pieces

In small bowl, combine dressing mix, water and oil; mix well. Cut steak into 1 1/4  x 1-inch pieces. Alternately thread beef and vegetables onto four 12-inch metal or wooden skewers (soak wooden skewers in water for 30 minutes prior to using). Brush kabobs with dressing mixture. Place kabobs on grill over medium, ash-covered coals. Grill, uncovered, approximately 10 to 12 minutes for medium-rare to medium doneness, turning occasionally.