In a medium saucepan, combine all of ingredients except for the jalapeños and onion, and bring to a boil, stirring to dissolve the No Salt and sugar.
Add the jalapeño slices and onion to the brine, stirring frequently, and boil for about 8 to 10 minutes until they turn that pea soup color you're accustomed to seeing in store-bought canned jalapeños.
Once they are the right color/consistency, remove from heat, cover, and allow to soak in the brine for about 10 minutes.
Carefully transfer jalapeños into mason jar and funnel brine into the jar. Leave uncovered and let it cool to room temperature before covering.
Once jar is room temperature, cover, and place in the refrigerator.
Best if refrigerated for about 8 hours before eating.
Recipe by SoFabFood at https://sofabfood.com/simple-low-sodium-pickled-jalapenos-recipe/