@ossobuco,
I am familiar with kale. It was a decent leaf to munch on when raw and well washed, worked better when placed on a sandwich with a few slices of raw onions.
Mother, she always drank the veggie water afterwards of cooking. It was salt free as she didn't like salt. Kale, beet greens, spinach...all the leafys that she could get her teeth on. Who can forget that tragic day we had to head outside and pick dandelion greens? (apparently, I can't forget) She never cooked delicious beef tongue; I had to visit my grandmother for that delight.
Congratulations on finding a new treat for yourself and a healthy one at that.