In a blender, combine all ingredients for the marinade. Measure out a 1/2 Cup, Reserve the rest.
Alternately thread chicken cubes, tomatoes, mushrooms, peppers and onions onto the skewers. Place on a baking pan. Coat with the 1/2 C marinade. let sit at room temperature for 10 minutes or keep wrapped in the fridge for up to 4 hours.
Heat grill to high, or preheat the broiler to high.
Place kebabs directly on the grill (or under the broiler) and leave undisturbed for 4-5 minutes. Turn over, and continue to grill until the chicken is cooked through, about 4 minutes more (the center should be opaque and firm).
Drizzle with reserved marinade. Serve with potatoes or corn on the cob.