
Marinate the steak. Use a sharp knife to cut the steak into 1 ½-inch cubes. Next, combine the olive oil, Beef Rub, brown sugar, Worcestershire sauce, balsamic vinegar, garlic, red pepper flakes, and fresh rosemary in a large bowl or gallon-size zip-top bag. Toss the steak pieces in the marinade, then cover or seal and place in the fridge for at least 1 hour, or up to 4 hours.
Marinate the vegetables. Add the vegetables to the steak and marinade ingredients and toss to thoroughly coat. You can allow the veggies to marinate for 10 to 15 minutes if you like.
Prep the grill. Preheat your grill to medium-high heat (about 400 to 450 degrees F). Clean and oil the grates to prevent sticking. If using wooden skewers, soak them in water for at least 30 minutes before threading.
Thread the kabobs. Remove the steak and vegetables from the marinade, shaking off any excess, then thread onto skewers, alternating with the kabob ingredients for variety and color.
Grill the kabobs. Place the kabobs on the grill and cook for 8 to 12 minutes total, turning every 2 to 3 minutes to ensure even cooking on all sides. Cook to your desired doneness (125 degrees F for medium-rare, 135 degrees F for medium).
Rest and serve. Remove the kabobs from the grill and let them rest for 3 to 5 minutes before serving hot.