I am trying some mustard greens (Kyoto Mizuna and Purple Osaka) (this is my first garden) for the cooler weather. (I have them in pots [as with some kale and collards] waiting for my zucchini and tomatoes to finish.)

My question is, how do I harvest mustard greens?

That is, my directions for collards and kale both say to harvest outer leaves and let the inner ones grow. Are mustards like that or do you just cut them down and eat them as a head as with lettuce?

Thanks