Wear gloves to protect your hands first.
Chop banana peppers into small pieces now.
Chop bell peppers, onion, and garlic finely now.
Add vinegar and sugar to a saucepan carefully.
Stir in salt, mustard, and celery seeds slowly.
Add chopped peppers, onion, and garlic gently now.
Bring the mixture to a boil slowly now.
Lower heat and simmer for 10 minutes gently.
Stir the banana pepper relish recipe mixture often carefully.
Remove from heat and cool slightly before jarring.
Use a funnel to fill jars neatly now.
Seal jars and store in the fridge quickly.