Rinse and drain the kale and remove some of the stems but not all. Chop coarsely.
In a large bowl, mix the kale with the salt and gently massage it until the vibrant green color comes up and the kale is soft but you haven't lost much of the volume. Don't over rub.
Mix the vinegar, juices, honey, pepper and mustard. Whisk in the oil. Add the currants and let them stand in the dressing until it's time to serve.
Drain the excess water from the kale. Combine with the dressing, being sure to distribute the currants well. Taste before adding any more salt.