Slice bok choy and cabbage, putting the stems and leaves in a separate bowl. Add oil, umeboshi vinegar, mirin, garlic, honey, sugar, parsley, onions. Stir fry onions for 5 minutes. Add bok choy and cabbage stems. Stir fry for 3 minutes. Add leaves. Stir fry for 2 minutes. Add tofu and stir fry for 2 minutes.