Bring to a boil the vinegar, pickling spice, sugar, and salt.
Meanwhile, finely dice the onion, celery, carrots, and garlic.
As soon as your vinegar brine comes to a boil, strain to remove the pickling spices and then add the diced vegetables. Return to a boil and then immediately remove from the heat. Let cool and place in the refrigerator overnight to pickle.
The next day, strain the pickled vegetables and reserve the brine. The brine is delicious and can be used again to make even more pickles, salad dressings, or add a splash of acid in any recipe.
Buy as many different kinds of canned and jarred olives that you can. Drain and pit them if necessary and then roughly chop all together. In a large bowl, add the capers, pickled vegetables and enough extra virgin olive oil to cover.
I store this olive salad in a crock in the refrigerator. It keeps for months at a time since it is covered in oil and gets better the longer it marinates. I recommend making this a week ahead, or better yet keep some on hand at all times!