Shallot bulbs. 1kg. Harvested in May of this year.

Scallion bulbs: Appropriate amount (approx. 100g-200g)
Sweet and sour sauce (pickling liquid):
Vinegar: 3 tablespoons
Sugar: 2 tablespoons
Salt: 1/2 teaspoon
Water: 1 tablespoon
(※If using commercially available Kantan-su or Rakkio-su, use as is.)

Cookpad
Instructions
Preparation: Wash the scallion bulbs, remove the root hairs, tough tips, and outer thin skins.
Removing bitterness: Briefly blanch in plenty of boiling water for about 10-20 seconds, then drain in a colander and pat dry thoroughly.
Pickling: Place the bulbs and the prepared sweet and sour sauce in a resealable bag (with a zipper), remove the air, and seal tightly.
Resting: Refrigerate for half a day to 1 day to allow the flavors to meld for delicious consumption.