Place your steak and vegetables into a plastic zip-lock bag or container with a lid.
Mix together marinade ingredients and add this to the bag/container with the steak and vegetables. Refrigerate for up to 6 hours.
If using wooden skewers make sure they have been soaking in water for at least 30 minutes prior to skewering your kabobs.
When ready to make kabobs, drain the steak and vegetables from the marinade and pat dry with a paper towel.
Thread the steak and vegetables onto the skewers making sure each skewer has a balanced amount of the meat and vegetables and you are alternating different ingredients for variety.
Brush each kabob with olive oil and then season each one with salt, pepper and garlic powder making sure to coat each one evenly.
Place the skewers onto a medium heated grill for around 10-15 minutes or until your preferred doneness. Make sure you are rotating each skewer so that all sides are cooked evenly.