Being a devoted Chicago girl at heart - married to a Sicilian no less - I love giardiniera. It is colorful and oh so versatile. Any time I want heat (which is often), I add a spoonful of the deliciously spicy hot oil from the giardiniera and/or the actual vegetable mixture as well.
I like a combination of bell peppers (multiple colors), jalapenos, celery, carrot, onion and cauliflower. By mixing with garlic, red pepper flakes, dried oregano, tellicherry black pepper and some pimento-stuffed green olives, it develops a complex flavor. Next, I combine all of this with some white wine vinegar and olive oil, to end up with a fantastic giardiniera.
KEY NOTE: This combination of goodness has to be refrigerated for at least two days before using to ensure that all of those delicious flavors effectively meld together. Enjoy!