A mixing bowl is filled with banana peppers, green bell peppers, red bell peppers, onions, garlic, and pickling salt. All ingredients should be mixed together using a spoon and covered with plastic wrap.
Sit them for one to two hours, then strain off all liquid after that.
Put apple cider vinegar, white sugar, and mustard seeds in a stockpot and boil.
Reduce the heat to low and simmer the pepper mixture for 25 to 30 minutes.
Allow them to cool for a while after you turn off the heat.
Cover the prepared jar with a lid and place the relish inside.
The jar should be processed in a hot water bath canner.
It is recommended that 8-ounce and 16-ounce jars be processed for ten minutes and fifteen minutes, respectively.
For the pickled process to be completed, the banana pepper relish should rest for 7 days after the canning process is completed.
It will be ready to use after 7 days.