Mix marinade Ingredients together in a large bowl.
Add mushrooms, chicken and peppers and stir until well coated. Cover and leave to marinate for at least 30 minutes, stirring occasionally.
Thread onto 8 skewers alternating the mushrooms, chicken and peppers. Cook on a sheet of foil on a medium hot barbecue (or under the grill) for about 6-7 minutes on each side.