I'm currently feeding my cories shrimp pellets, which they quite enjoy, and they go after leftovers from feeding time, but i feel they might need some sort of vegetable supplement. Suggestions?
Algae wafers, probably your best bet. Generally they won't go out of their way to eat any veggies offered. If you want to vary their diet more, try live blackworms or frozen bloodworms and brine shrimp.