Zesty Zucchini Relish

Gather the necessary ingredients and prepare them for use. \nTransfer the zucchini and onion to a large, non-reactive container; sprinkle salt liberally over them. Using your hands, thoroughly mix the salt with the zucchini to ensure an even distribution of seasoning. Cover the container and refrigerate it overnight, allowing the flavors to meld together.\nDrain the zucchini in a colander and rinse it thoroughly with cool, running water. Remove any excess moisture from the zucchini using a clean kitchen towel or paper towels; set it aside for later use.\nCombine the sugar, vinegar, red and green bell pepper, and cornstarch in a large cooking vessel. Add the celery seed, nutmeg, turmeric, and black pepper to the mixture; stir until everything is well combined. Then, add the drained zucchini to the pot and bring the mixture to a boil over medium-high heat. Once boiling, reduce the heat to a lower setting and let it simmer for 30 minutes.\nSterilize seven 1-pint jars and their corresponding lids. Fill the jars with the relish mixture, making sure to eliminate any air pockets or spaces. Fill the jars completely, leaving no room for excess liquid. Secure the lids tightly onto the jars.\nPosition a rack in the bottom of a large stockpot and fill it halfway with boiling water. Carefully lower the jars into the pot using a jar holder, leaving at least 2 inches of space between each jar. If necessary, add more boiling water to cover the tops of the jars by 2 inches. Bring the water to a full boil, then cover the pot and process the jars for 30 minutes.\nRemove the jars from the pot and place them on a cloth-covered or wooden surface, several inches apart. Allow the jars to cool completely before handling them. Once cool, press the top of each lid with your finger to ensure a tight seal; the lid should not move up or down at all.