Passata is puréed tomatoes that have been seasoned.
- Place the onion and olive oil in a microwave bowl. Cover and cook for 1-2 minutes, until soft.
- Place the chicken in a large slow cooker. Top with the onion and vegetables. Add the passata, tomato paste, herbs and olives and stir to combine. Cover and cook on low heat for 6 hours. The juices may be thickened with 2 tablespoons of cornflour mixed to a paste with a little water. Add about 30 minutes before the end of cooking. Great served on potato mash or rice.