Cut the sirloin into 1 1/2-inch chunks and place in a large bowl.
Combine all the remaining ingredients and mix. Pour over the sirloin pieces and let marinate for 1-3 hours.
Remove the beef from the refrigerator 30 minutes before cooking.
Preheat the grill to medium high while you prepare the skewers.
Divide the marinated sirloin pieces between 8 skewers. When all the beef kebabs are complete, season with salt. Place them on the grill and cook them for approximately 6-8 minutes, turning them every 2 minutes. Cook to your desired temperature. Color is not an accurate indicator of final cook temperature. Ensure final cook temperature reaches 145 F for 3 minutes.
Remove from the grill and serve.
If using wooden skewers, soak in water for 10 minutes before putting the beef on and cooking over the grill. This will help prevent too much burning of the wooden skewers.