8 (8-inch) bamboo or metal skewers, or long sturdy rosemary sprigs
3 tablespoons balsamic vinegar
2 teaspoons olive oil
2 teaspoons chopped fresh rosemary leaves
1/4 teaspoons salt
1/2 teaspoons coarsely ground black pepper
1 1/2 pounds beef eye round roast, trimmed of fat, cut into 1-inch cubes
1 package (10-ounce) white mushrooms, each cut in half
1 medium orange pepper, cut into 1-inch pieces
In medium bowl, whisk vinegar, oil, rosemary, salt, and pepper until blended. Add beef and toss to coat. Cover and refrigerate at least 30 minutes or up to 4 hours, stirring once halfway through marinating.
Prepare outdoor grill for direct grilling on medium, or heat ridged grill pan on range on medium-high until hot.
Alternately thread beef, mushrooms, and pepper on skewers. Brush with any remaining marinade.
Place skewers on hot grill grate and cook 6 to 8 minutes, for medium-rare or until desired doneness, turning to brown all sides.