Combine 600 ml water, 200 ml soy sauce, 200 ml sugar (or allulose), and 200 ml vinegar in a pot and bring to a boil. Let it cool while preparing the vegetables.

Slice 3 bell peppers, 1 onion, and 10 green chilies into similar thickness strips.

Pack the sliced vegetables tightly into a storage container.

Pour the cooled pickling sauce over the vegetables until fully submerged.

Let the pickles sit at room temperature for 24 hours, then transfer to the refrigerator.