I only know of one way of eating kale (I know it as boerekool) and that's the traditional Dutch way.
Mash it with potatoes and eat with jus (gravy) and rookworst (smoked sausage). And always with a bit of vinegar sprinkled on it.
I used to like it a lot, till my dad planted too much and we were eating it twice a week or more!
We only ate it in wintertime and only once the frost had gone over it. I don't recall any bitter taste at all, but it was said that the frost...