Look for mizuna (an Asian salad green) and kohlrabi (a mild relative of the turnip) at Asian or farmers' markets to create this salad with pomegranate seeds.
Using a mandoline or a sharp knife, thinly slice the celery and kohlrabi. Cut kohlrabi slices into 1/4-inch-wide strips.
Halve pomegranate; remove enough seeds to yield 1/2 cup (reserve remainder for another use). Add seeds, celery, kohlrabi, and mizuna to a serving bowl.
Whisk together vinegar, salt, pepper, sugar, and mustard. Whisking constantly, add oil in a slow, steady stream; whisk until emulsified. Toss with salad.