Tomato sauce base:
1) Heat a large saucepan and add the olive oil and anchovies. Stir the anchovies into the hot oil to dissolve.
2) Add the onions, celery and carrots and cook until they begin to brown. Add the basil leaves, garlic and chilli flakes, and sweat to release their aromas. Add the sachet and tomatoes, and season with salt and pepper.
3) Simmer for 45 minutes until the vegetables are tender enough to easily crush with a fork. Remove the sachet and pass the sauce through a fine food mill. Reserve.
In a separate saucepan, combine the wines and saffron. Reduce the wine by half. Add the fish stock and the reserved tomato sauce, and bring to a simmer to combine the flavours. Check the seasoning and adjust if necessary.
1) Place the cioppino base in a large straight-sided pot. Heat to just below a simmer. Add the fish, clams, mussels, crab and prawn tails to the pot. Cover and steam or poach the seafood briefly to cook and heat through each item. The clams and mussels should be now open; the fish and prawns should turn opaque.
2) Add the calamari for the last minute of cooking. Discard any clams or mussels that are still closed or do not have beautiful plump meats.
1) Heat about 15cm of oil to 185C. Clean the back apron of the prawn head and clean inside the tail end of each head.
2) Lightly dredge the prawn heads in potato starch and fry for 3 minutes until very crisp and golden. Drain briefly, split in two and season with salt and pepper. Hold warm for service.
Spicy prawn rouille:
Soak the bread cubes in the fish stock and place all of the ingredients except the oil in a blender. Puree the ingredients into a paste. Pour in the oil slowly, while blending, to make a thick fluffy mayonnaise sauce.
Rub the bread with the cut garlic clove and brush with the melted butter and olive oil. Sprinkle with parsley, salt and pepper and toast to golden brown in an oven or toaster oven.
Ladle the cioppino sauce into hot serving dishes. Arrange the fish items on each dish from the back of the dish to the front. Lean the crostini against two pieces of sea bass. Arrange three split fried prawn heads against the crostini, facing forward and upright. Add one mussel shell and mussel meat, and one clam shell and clam meat. Add the peeled prawn tails, last piece of fish, calamari and peeled crab legs.
Top with the chopped parsley, cover and serve. Serve with the lemons and spicy rouille sauce on the side.