Thanks for sharing the great info @bobydimitrov! I've only eaten salsify a few times from a Dutch farmer who grew it in southern Canada. Quite nice indeed.
As far as I've read the sea kale was covered and blanched to create more tender shoots in early spring. These young shoots were the chosen food, not so much the leaves. Save your blender the trouble!
As for dandelion, you're lucky. We don't really have any on our property. So we're choosing varieties with bigger more tender leaves. We'd be happier if they already grew here though. ;)