Fillet the John Dory. Skin each fillet and separate into 3 pieces on each side. Cut each fillet into thick strips to give at least 24 pieces of equal size.
Cut the calabrese into small florets and ‘turn’ the stalks into small barrel shapes using a small knife. If there are any leaves save these and use them to garnish the finished dish. Lightly blanch both the florets and the ‘turned’ stalks in boiling salted water – the florets for 30 seconds, the stalks for 1 minute. Refresh in iced water, drain and dry them off in a cloth.
Place the strips of fish in a poaching tray, season and add the fish stock and white wine. Cover with buttered paper or foil and place over a high heat until the liquid starts to tremble. Hold it at this point and allow to cook for 1 minute. Carefully drain the fish from the stock, cover and keep warm.
Return the stock to a high heat and reduce until syrupy. Pour in the cream and reduce again over a high heat until it starts to thicken.