While this Giardiniera was originally intended to go along with the Slow Cooker Italian Beef recipes (this one made with vital wheat gluten and this one made with washed flour), it makes an amazing topping for sausages, deli meats, salads, and just about everything when you're looking to add some crunch and kick!
Add all of the vegetables through the peppers to a large, non-reactive bowl and sprinkle with salt. Mix to evenly coat. Cover the veggies with cool water and a lid or plastic wrap, and put them in the fridge for at least 8 hours or overnight.
The next day, rinse the vegetables very well. In a bowl, add the garlic, pepper, oregano, and olives if using. Pour in the vinegar and olive oil and mix well. Cover the bowl and put it back in the fridge for at least a day (longer is better), mixing them up once in a while if not fully-coated.
Bring to room temperature before serving. Anything leftover that you're not using right away can be kept in sealed jars in the fridge for up to one month. It's awesome not only on Italian beef sandwiches (like this one made with vital wheat gluten and this one made with washed flour), but also sausages, deli meats, salads and more!