2 lb sirloin steak or chicken or a combo of each, cut into 1-inch cubes
1 red bell pepper, seeded and cut in 1-inch pieces
1 orange bell pepper, seeded and cut in 1-inch pieces
1 green bell pepper, seeded and cut in 1-inch pieces
1 red onion, cut in 1-inch pieces
8 (12-inch) metal skewers
In a medium bowl, whisk together olive oil, balsamic, garlic and pepper. Add the cubed sirloin steak or chicken to marinade and toss to coat. Cover with plastic wrap and let marinate for 30 minutes or up to 1 hour.
Once the meat has marinated, thread it onto the skewers alternating with pieces of bell pepper and red onion.
Grill kabobs over medium heat, turning often until all sides of the meat are well-brown and vegetables are tender. (About 12 to 15 minutes)