Heat the oil in a large saucepan, add the onions, capsicum and celery and cook for 5–6 minutes or until lightly browned. Stir in the garlic and bacon and cook for a further 3–4 minutes. Stir in the flour, increase the heat slightly and cook for 2 minutes, stirring. Stir in the paprika and cook for 2 more minutes. Gradually add the stock and water, stirring well to dissolve the flour mixture.
Add the thyme, tomatoes, parsley, bay leaves and Worcestershire sauce. Bring to the boil, then reduce the heat to a simmer and add Tabasco to taste. Stir in the okra slices and simmer for 15 minutes or until the okra is tender and the mixture has thickened.
Add the prawns and green beans and cook for 3 minutes or until the prawns turn pink and the beans are tender. Remove the bay leaves and season the gumbo with salt and pepper to taste. Serve in bowls, sprinkled with spring onions.