Cut the peppers into strips and the onion into wedges.
Preheat the oven to 200°C.
Heat one tablespoon of oil in a large casserole or oven- & flame-proof dish. Season the chicken pieces and sear them in half of the oil until light brown, then transfer them onto a plate.
Pour away the fat and heat the remaining oil, then soften the onion and pepper for about 5 minutes.
Add the garlic, stir for 1 minute. Add the tomatoes, wine and stock to the saucepan and the chilli if used. Bring to the boil and mash the plum tomatoes into chunky pieces. Season with salt and pepper, add the rosemary & bay leaf.
Return the chicken pieces to the pan; put them on the top of sauce, then cover the pan with a lid or foil and put it the oven for 30 minutes.
Remove the foil or lid, turn over the chicken and scatter the olives around it. Bake for 15-25 minutes until the chicken is golden and the sauce has thickened.
Sprinkle with the chopped parsley before serving.