first off how big is your tank as this may affect the morays feeding as it might be a phychologocal issue with the tank size or bad water conditions in a small tank
How big is the eel? If over 3 ft feed once a week ish, but if under 3ft then feed twice a week with tongs as 1guydude said - feed shrimp, squid, crab, fish and krill to keep your eel healthy and a varied diet.
Just keep in mind this eel gets about 4ft in lenght and its girth is MASSIVE when fully grown which means a protien skimmer and extremely good filtration will be needed if not already obtained.
hope this helps