Gently heat the oil in a large heavy-based pan or flameproof casserole dish. Stir in the onions then cook for 5 minutes. Add the green capsicum, celery and ham and cook for a further 4–5 minutes until the vegetables are soft.
Sprinkle with the flour and cook, stirring for 2–3 minutes. Stir in the tomatoes, stock, rice and Cajun seasoning. Bring to the boil then reduce the heat. Cover and simmer for 15 minutes or until most of the liquid is absorbed and the rice is almost tender.
Stir in the prawns, cover again and cook gently for 3–4 minutes, or until the prawns have turned pink and are just cooked.
Gently stir in the crabmeat, cover the pan and cook for 1 minute. Remove the pan from the heat and let stand for 3 minutes. Serve sprinkled with chopped coriander. If you like, garnish with coriander sprigs.
• Use cooked prawns if they are a better price. Add in step 4, so they just heat through for 1–2 minutes; any longer and they will toughen. Alternatively, you could use frozen prawns but make sure to thaw and drain them before use. • Use some chopped bacon or chorizo sausage in place of the ham, if you prefer.