When I got my first eel I never saw him eat. Earth worms (red wigglers) will never be refused. I would get you some from a bait shop (cheeper). Clean about 10 of them and just drop them in the tank in font of him and his hiding space. Move away from the tank and sit real still. He should come out in about 5 mins to feed, if not turn the lights off and let him be for about 3 days. The worms will not die in there. They will bury down in the substrate and the eel will hunt them. I love watching mine hunt for worms

After 3 days see if you can dangle one in font of him and see if he will eat it. A 7" eel can eat a 12" earth worm as long as its not a night crawler. Night crawlers are way bigger than earth worms. When the eel gets bigger you can feed them to the eel