Bring 6 cups of water to a rolling boil.
Once cabbage is very finely shredded, place it in a fine mesh strainer and place it over a large bowl. Carefully pour the hot water over the cabbage. Then rinse the cabbage with cold water over the sink, and try to drain out as much water as possible.
Place the drained cabbage into a large bowl and add in your shredded carrots, sliced onions, jalapenos, Oregano, and salt. Next, pour the vinegar over the slaw mixture.
Use a large spoon or gloved hands and mix the slaw until everything is fully combined. You can also place a lid on the bowl and shake until it is all completely mixed up.
Add the curtido to large glass jars with lids, or a bowl with a lid, and refrigerate it until you are ready to use.
Curtido is absolutely delicious after it rests overnight, or for a few hours before enjoying.
Store in the fridge for up to one week.