You can make this without the sweetener, if you like. Collards would also work here, as well as daikon greens, rapini–the sturdier greens.
1 – 2 bunches kale
1 T salt
2 T sugar or honey or agave
1 c boiling water, plus extra if needed
3 T olive or other oil
4 T white wine vinegar, or rice vinegar, or cider vinegar, or herb-flavored vinegar
assorted shredded roots–daikon, carrot, turnip, celeriac, kohlrabi… (optional)
1. Wash, stem, and coarsely chop kale. Put into a large bowl and add salt and sugar. Massage these into the kale, gently, until some green liquid is released from the kale. This will take a few minutes. Try not to squish or bruise the leaves. Set aside.
2. Combine boiling water, oil, and vinegar.
3. In a quart jar, transfer the kale leaves, pressing down gently so that they are firmly packed. Pour the marinade over. If the liquid does not cover the kale, boil up enough extra water to cover. Don’t fill to the very top, allow some headspace. Let the mixture cool, then cover and refrigerate for a day, if possible. The flavor will improve with age.
4. Serve as is, draining the kale first, if you like. The kale is also good mixed with some shredded roots.