Shred the chicken meat (no skin) and set aside.
Finely chop the onion, garlic, celery and carrot.
Heat the oil in a large saucepan and gently sauté the chopped vegetables until tender.
Stir in the dried herbs, then add the chopped tomatoes and chicken stock (or leftover gravy). Bring to the boil and gently simmer for 15 minutes, or until the veggies are cooked through.
Add the fresh herbs and, using a stick blender, purée the stew into a thick sauce. You can set aside the sauce until you’re ready to make the stuffed peppers.
Add about a ladleful of the sauce to the shredded chicken, toss well. Mix in the olives and season with salt and pepper.
Cut off the tops of the bell peppers and remove the seeds and any inside ribs. Stuff the peppers with the chicken mixture.
Add the extra cup of chicken stock to the tomato sauce. Add more if it’s still too thick. Place the stuffed peppers in the tomato sauce, put a lid on and bring to the boil. After 5 minutes of steaming, scatter your chosen green vegetables around the peppers and cook for another 5 minutes or so. The peppers should be tender - not too soft!
Serve warm with freshly ground pepper and chopped parsley scattered on top.