Add chicken to a ziplock bag. Pour in olive oil, 2-3 tbsp red wine vinegar, oregano and salt & pepper.
Add vegetables to the bag and squishy to blend all flavours.
Marinate for a minimum of 30 minutes on counter or longer in the refrigerator.
Preheat your grill to medium high and start threading your skewers alternating veg/chicken. Grill skewers turning occasionally until chicken is browned and cooked through (about 10 minutes).