I got him to eat a minnow yesterday. After letting the minnow swim free in Edwardos tank, but never getting close enough to get eaten.....I was able to put the expired minnow on a piece of fishing line and offer it to Edwardo. I wasn't sure it was going to work since my hand was in the tank, but he immediately walked out of his cave and Boom, Bam, Pow he ate it in one chomp. I might try a thawed silverside in this manner next and see if he'll take it. But I need to wait a few days as to not overfeed him.
I think I might try some brackish mollies next as they might be able to free swim for longer than 2 minutes.