Add all marinade ingredients into a mixing bowl and whisk thoroughly.
Add the cubed steak pieces to the marinade and coat thoroughly
Let the steak marinate for 3-4 hours in a covered bowl in the fridge
In a separate bowl, mix the sliced vegetables, salt, pepper, and garlic powder
Begin assembling the kabobs on skewers, alternating vegetables, and steak
Heat the grill to medium
Cook skewers over heat for 12-15 minutes, until the steak is fully browned and vegetables are cooked
Allow the kabobs to sit for 3-4 minutes before serving