My large moray in my brackish tank (about 16 inches) eats every day. Eats a chunk of seafood about one inch cube. Diet depends on the day. That is an aggressive feeding schedule though, as he is still growing well in his new tank. If he doesn't want it, he'll leave it alone and won't eat for a couple days.
I asked on this board a few days ago about my new snowflake eel, was told he wouldn't eat himself to death either.
So I presume your chainlink would be about the same. Silver sides are pretty small, you should be able to feed him more than a piece of silver side. I thaw out frozen silver sides (about three inches long, really skinny) and feed about four or five to my tiny SFE every couple days. You should be able to up the feeding to 3-4 times a week, and a little more food.
It also depends how your eel is acting? Is he acting like he is hungry? ie- swimming around a lot, at the surface, etc.