Prepare and salt the cabbage
If the cabbage cores stick out too much, trim them off with your knife over your cutting board.
To split a cabbage in half without shredding the densely packed leaves inside, first cut a short slit in the base of the cabbage, enough to get a grip on either half, and then gently pull the halves apart so the cabbage splits open.
Cut a slit through the core of each half, 2 inches above the stem. You want the cabbage leaves to be loose but still attached to the core.
Dunk the halves in a large basin of water to get them wet. Sprinkle salt between the leaves by lifting up every leaf and getting salt in there. Use more salt closer to the stems, where the leaves are thicker.
Let the cabbages rest for 2 hours. Turn over every 30 minutes, so they get well salted. From time to time you can ladle some of the salty water from the bottom of the basin over top of the cabbages if you want to.
After 2 hours, wash the cabbage halves a few times under cold running water. Giving them a good washing, to remove the salt and any dirt. As you wash, split the halves into quarters along the slits you cut into earlier. Cut off the cores, give them a final rinse, and put them in a strainer over a basin so they can drain well.

