Hikari carnivore sinking pellet cut in half if your poly is under 3", tilapia cut in small cubes depends on the size of the poly. Some poly will eat algae wafers just from curiousity but they wont really eat veggies. Peas i havent try but
tlindsey
mentioned some will eat it some wont. Live nightcrawlers are good source of protien cut it to small poeces depends on the poly size but if you want to see your poly deathroll then putt the whole worm,
