Cook the bacon grease and flour together in a large pan over a medium heat until the roux mixture has turned a golden brown colour

Add the chopped vegetables and cook down until the roux has turned a deep brown, around 3 more minutes

Stir in the stock, chopped tomatoes, Worcestershire sauce, kielbasa, chicken and seasonings

Cook at a simmer for 15 minutes then add the prawns and cook a further 10 minutes until they're pink and done

Serve over white rice

In the USA they use Filé powder to thicken their gumbo. We don't get that in Britain but you can use 1 tbsp cornflour / cornstarch mixed with a few tbsps cold water if you want to instead. Just stir it in while the pan is simmering and it'll thicken the gumbo