Heat 1 tbsp of the oil in a large casserole or frying pan and cook the chicken to brown for a few minutes. Tip on a tray. Add the onion to the saucepan with 1 tbsp more oil and fry for 5 minutes until almost relaxed. Add the celery and fry for another 2 minutes, then tip out to join the chicken. Add the remaining oil, bay leaves and flour to the pan and boil in a paste. Continue cooking, stirring continuously (with a splash of water if needed) until golden brown, then stir in the spices for 2 minutes.
Gradually stir in the inventory until smooth and sauce. Return the chicken and veg to the pan along with the peppers, cover and cook softly for 15 minutes. Stir in the ham, cover and simmer softly.