Curtido is a Central American form of lightly fermented cabbage that is commonly served as a condiment in various dishes including pupusas. It is similar to sauerkraut or tart cole slaw or even kimchi. I like that it's super easy to make where you pretty much just mix some shredded cabbage, carrots and onions along with vinegar, water, salt and oregano and let it sit for a few days before enjoy as a side or as a condiment/relish on whatever you wish!
Click here for this recipe: http://www.closetcooking.com/2016/08/curtido.html