Recipes for giardiniera vary all over the map. Some refer to the type used on hot steak sandwiches, subs and other sandwiches as a condiment, which is what this recipe is about, while others refer to a vegetable mix served cold as part of an antipasto, or by itself as an appetizer or snack.
I have modified and combined a variety of recipes I found on the Internet and I tried this recipe as a condiment on an Italian sub and on a shaved steak sandwich and on other hot sandwiches. It is delicious! This one you definitely want to make. Use it generously on any of the suggested sandwiches.
The recipe as provided below calls for a few days of refrigeration to marinate it and then using all of the product within a week to avoid spoilage. That is okay if you plan to consume that much product but I like to make it once and have it available for months. After making the hot giardiniera I simply pasteurized it at 180 degrees F for 30 minutes, chilled it overnight, covered, and then I vacuum sealed one cup quantities in small vacuum sealing bags. Thus, simple refrigeration provides a shelf life of at least two months, which makes a lot of sense to me. Also, pasteurization instead of traditional canning retains the texture and taste of the individual ingredients in the hot giardiniera, which is then perfect. That is why I choose pasteurization. But the choice of which method to use is up to you. You may, if you want, can the product and sacrifice some taste and texture.
The very best method for pasteurizing foods with a high solids content is a way I just developed and used for the first time today, and I highly recommend it. I made the hot giardiniera condiment using the ingredients and the early parts of the directions shown below, but once everything was mixed in raw state I vacuum sealed the product in one cup quantities creating flat bags of it about 3/4 of an inch thick and roughly four inches on each side. I then placed those bags individually, one layer deep and not touching each other, into the microwave oven to preheat them. I did them four at a time and gave them one minute on high heat on each side, for a total of two minutes. Then I put the heated bags onto heated cookie sheets in a 185ºF oven set to the convection setting. I set a timer for one hour to give the product time to elevate in temperature from about 150ºF to 180ºF (about 30 minutes), and then time to pasteurize (the last thirty minutes). I then removed the bags from the oven and placed them individually on a granite counter to cool to room temperature. I then put them into the refrigerator. Having used the optional sodium benzoate solution listed below I now have a product that will easily last from six months to a year, refrigerated.
Ingredients: (makes one gallon)
Place the processed yellow and red peppers, jalapeno peppers, celery, carrots, onion, and cauliflower into a large bowl.
Add the canning salt to the bowl and mix well by hand.
Fill the bowl with enough cold water to cover the vegetables, then cover the bowl with plastic wrap and refrigerate the mixture overnight.
The next day, drain the salty water, rinse the vegetables and drain well.
Process/Chop the capers, garlic, peperoncini and the two types of olives and put them into a large bowl.
Add the oregano, red pepper flakes and black pepper and mix well.
Add the vinegar and olive oil and mix well. Combine that mixture with the vegetable mixture and mix well.
Cover the hot giardiniera with plastic wrap and refrigerate it for 2 days before using it (or pasteurize and process it like I do).
You use this condiment by putting the amount of your choice (be generous) on a sandwich like an Italian Sub.
If you store the hot giardiniera in a jar with a tight fitting cap and keep it refrigerated it will be okay to use for one week.
Enjoy! You will enjoy it much longer if you vacuum seal and pasteurize it and then refrigerate it as I do, as explained earlier in this recipe.