Cories usually get most veggies. Same with plecs, varieties!
have you tried cooked peas? They love it! Also, try many types. Like, this is what I use to do. Slice a LITTLE TINY PIECE of veg/fruit.
Then, put it on a skewer and dip it in, if the fish aren't interested in at least four minutes I take it out.
(I learned that larger fruits/vegs won't catch a fish's attention.)