Cut the chicken into 2cm cubes. Sprinkle with the Cajun seasoning and the sage, making sure that the chicken is coated all over. Heat 1 tablespoon of the oil in a large flameproof casserole dish over a medium–high heat, add the chicken and fry for about 5 minutes, stirring frequently, until the cubes are browned on all sides. Remove from the pan with a slotted spoon.
Add the remaining oil to the pan with the onion, green capsicum and celery, then fry for about 2 minutes, stirring. Add the garlic and basmati rice and fry for another minute.
Pour in the stock and stir well. Return the chicken to the pan. Bring to the boil, then reduce the heat, cover and simmer for 15 minutes. Add the ham and canned tomatoes. Cook, covered, for a further 5–10 minutes or until the rice has absorbed all the liquid.
Season to taste with Tabasco and a little salt and pepper. Serve sprinkled with the spring onions and parsley.