Giardiniera is an Italian-American style of pickled vegetables. Italian Chicagoans popularized the condiment. It generally consists of a few different pickled vegetables, including carrots, sports peppers, chile peppers, celery, cauliflower, and/or bell peppers that is then marinated in olive oil. Depending on the heat level you prefer, you will find a different variations with different peppers. This delicious condiment is super versatile, but you will most often find it on a Chicago style Italian beef sandwich.