Start by washing and thoroughly drying all your vegetables. Remove the seeds from the cucumbers and peppers, then finely dice the onions, cucumbers, and bell peppers into small, uniform pieces. Place all the diced vegetables in a large pot and sprinkle them with the ¼ cup pickling salt, stirring to coat evenly.

Fill the pot with water just enough to cover the vegetables, then cover the pot and let the vegetables soak for 2 hours. Once the vegetables are finished soaking, pour them into a large strainer, rinse them well under cold water, and let them drain completely.

Rinse your pot and place the apple cider vinegar and white granulated sugar in it. On medium heat, bring the mixture to a boil, stirring until the sugar has completely dissolved. Add the mustard seed, celery seed, and turmeric to the pot and stir, then boil for an additional two minutes.

Reduce the heat to low and add the drained vegetables. Bring the mixture to a simmer and cook for an additional 10 minutes, stirring occasionally. The vegetables should soften slightly but still retain some texture.

Spoon the hot relish mixture into three clean mason jars (two 32-ounce jars and one 8-ounce jar). Ensure that the liquid is distributed evenly among the jars, rather than adding too much to just one. Place the lids on tightly.

For Canning (Water Bathing): Water-bathe the jars for 10 minutes, with water reaching an inch above the jars while processing. Let them sit at room temperature with rings on for 24 hours, then remove the rings and check the lids for proper sealing. If they're sealed properly, store them in the pantry until needed. After opening, store the jar in the fridge for optimum freshness.

For the Refrigerator Method: Allow the jars to cool on the counter until they reach room temperature, approximately 2 hours. Re-tighten the lids and place them in the fridge. Let them remain in the fridge for 3 days before use for the best flavor development. Keep in the fridge for up to 3 months in sealed mason jars.