Kale leaves can be pretty tough if you don't prepare them right. You can easily tenderise them for your salad, without any heat, by giving the leaves a gentle massage.
Before it became super popular, kale was used for cooked dishes so the heat could soften up the rough leaves. This video from the America's Test Kitchen YouTube channel demonstrates two lesser-known techniques for making kale salad-ready. After you've removed the leaves from the stem, cut them into half-centimetre strips, and massage the leaves for a few minutes. Now you can have a tasty kale salad with a softer, more satisfying texture.
Preparing Kale for Salads [YouTube]