I would think the exact recipe might only be known by the head chef at the time on that particular ship you were on. If you could find that information (ship, date, head chef) then you might be able to contact someone at RC to see if you could get the recipe. It's a long shot though. Same thing happened to me on a cruise we went on with Azamara years ago but it was a potato soup. Best I've ever had before or since. Not sure what the secret ingredient was but it was great!!