Seafood gumbo

Step 1: Simmer the prawn shells with the 8 ¼ cups water and ½ onion for 30 minutes, then strain; you need about 1.5 litres. Keep the 2 lb raw prawns, shell on chilled.

Step 2: In a heavy pot, stir the ½ cup vegetable oil and 3 ½ oz plain flour over a medium heat for 25–30 minutes into a roux the colour of milk chocolate.

Step 3: Add the 2 onions, 3 celery sticks and 1 green pepper and stir 6 minutes until soft, then the 4 cloves garlic and 10 ½ oz okra for 5 minutes.

Step 4: Add the 14 oz tinned chopped tomatoes, the shell stock, 2 bay leaves, 1 tsp dried thyme, ½ tsp cayenne pepper and 2 tsp salt. Simmer 40 minutes until the okra has melted into the broth and thickened it.

Step 5: Add the prawns and simmer 3 minutes until pink and curled. Add the 9 oz white crab meat and 12 shucked oysters with their liquor; cook 2 minutes more, just until the oyster edges curl. Use oysters that smell fresh and briny, and throw out any that smell off.

Step 6: A common mistake is adding the seafood early, which turns prawns rubbery. Stir in the 4 spring onions and serve at once over 2 ⅝ lb cooked long-grain rice.