You CAN use canned peas and just squeeze the insides out, but frozen, blanched are better.
Take a few peas, and a teaspoon of hot water, put it in the microwave for about 10-15 second, let them cool, squeeze the peas til the inside pops out, either mash them, or leave them halved, depending on the size of your fish, throw the outer shell away, and dump them in your tank.
If they're not gone by morning, remove them and pitch them. (I use an aqua gardener thingy to get down there and grab them - I found out my Calvus do NOT eat vegetables. Meat only, please.)
Don't feed them the blood worms for a while and keep on offering the pellets and veggies. Eventually they will eat the pellets and whatever else you offer. My dads two just recently got his two large Oscars to eat pellet food instead of feeders by using this method.
so we didn't feed for 2 feedings (instead of 2 days just to see if it would work) and the Oscar has started to eat Hikari Cichlid gold! The Jack will eat the pellets the odd time but isn't completely sold yet! we are going to feed them tonight then stop for a day and see if they will eat peas, if not we'll feed them then wait 2 days and try again