Add the sliced zucchini to a large bowl then sprinkle it with 1 tablespoon kosher salt. Allow the zucchini to sit for 1 hour then rinse it with water and drain it.
Add the shallots and garlic to the bowl with the zucchini.
In a medium saucepot set over medium-high heat, combine 3/4 cup water with the apple cider vinegar, sugar, mustard seeds, celery seeds, turmeric, bay leaf and chili flakes (optional). Bring the mixture to a boil then remove it from the heat and let it cool for 10 minutes.
Pour the liquid mixture over the zucchini and shallots then allow the pickles to cool to room temperature before storing them in airtight containers in the fridge.
★ Did you make this recipe? Don't forget to give it a star rating below!