Slice the apple into quarters around the core. Slice the quarters into thin slices, then cut those into batons or matchsticks leaving a bit of peel on both ends. Place the apples in a bowl and squeeze half a lemon over them. Toss to coat.
Remove the stem ends from the bunch of mizuna, wash, dry, and chop into bite size pieces. Toss the mizuna with the apples.
Place the dressing ingredients in a small jar with a tight fitting lid. Shake to combine. Toss the mizuna and apples with the dressing. Garnish with sunflower seeds and dried cranberries.