Thinly slice your red onion, roughly ⅛” thick. Slice jalapeno in similar fashion.
Pour white vinegar and apple cider vinegar in a mason jar. Sprinkle in stevia. Then, tighten the lid and shake until the sugar is dissolved.
Place red onions, jalapenos, dill, salt, and pepper in the jar. Ensure that the vegetables are completely submerged.
Refrigerate for 24-48 hours. Once the onions are bright pink and tender, they'll be perfectly pickled! Enjoy!