If you're going to go to the trouble of making your own Italian Beef, the chances are there won't be any decent giardiniera anywhere near you. Its easy enough to make and even better than the storebought stuff.
Hot Giardiniera
There is no set amount for all of these vegies. You have to add an amount that looks right to you. Also you can add other vegies as you wish.
Cauliflower
onion
celery
carrot
red bell pepper
Combine the above ingredients in a bowl and add enough water to cover. Add salt. For every 2 cups of water, add 1/4 cup salt. Cover the bowl and let sit for 24 hours. Drain the water and wash the salt water off the vegies. Dump vegies into a bowl and add:
capers
green olives with pimento
sport peppers (substitute jalapenos)
pepperoncini peppers
fresh ground black pepper
red pepper flakes
oregano leafs
Place into a jar and add an equal amount of white vinegar and olive oil, enough to submerge the whole mess.