To prepare the brine, combine together the vinegar, sugar, mustard powder, mustard seeds and turmeric in a pot and bring to a simmer over medium heat. Let simmer for a few minutes, or until the sugar dissolves.

*Note: Depending on how sweet you like you pickles, you might want to add another 1/2 cup of sugar.

Once done, set aside to cool until it is just warm to the touch.

*Note: For the best results, use zucchinis that are not too large and seedy.

Wash and remove the ends from the zucchini. Using a mandolin, slice into 1/16th inch thick slices.

Thinly slice the onions and place into a large bowl with the zucchini. Add the salt to the zucchini and toss to evenly distribute the salt.

Next, add the ice cubes, followed by just enough water to cover the vegetables. Stir a few times to help distribute and dissolve the salt. Let stand for 1 hour.

To drain the zucchini and onions, simply pour into a sieve or strainer.

At this point, it is important to remove as much of the excess water as possible, otherwise it will dilute the brine. The easiest way to do this is to place handfuls of the zucchini and onions into a salad spinner. Gently spin them to remove any excess water. Alternatively, place the vegetables between paper towels to remove the excess water.

To finish the pickles, place the zucchini and onions into a large bowl and pour in the cooled brine mixture. Stir to combine the ingredients and then place into jars — ensuring that the brine solution completely covers the pickles.

Cover and refrigerate. Note that the pickles will benefit from at least 24 hours in the refrigerator before using them.

As time goes on, the zucchini will become infused with the spices and the onions will mellow out.