Prep the green onions: Cut the roots off the green onions, then either cut into small slices or cut in half lengthwise and then again into small spears or sticks (see photo for examples). Set aside.
Prepare the pickling jar: Add green onions to a large jar and add ginger, garlic, mustard seeds, and red pepper flakes (if using).
Prepare and add the brine: In a medium saucepan bring the water, vinegar, sugar, and salt to a boil. Once boiling, pour into the jar until the liquid completely submerges the onions. Close the lid on the jar tightl
Pickling instructions: Let the jar cool on the counter until it reaches room temperature. Once cooled, put the jar into the refrigerator and let the onions pickle for at least 2 hours before serving, but for best results serve after at least 24 hours. Quick pickled scallions are good up to one month in the refrigerator.
Vinegar: We chose rice vinegar in this recipe, but white vinegar, white wine vinegar, and apple cider vinegar are also tasty choices.
Recommended jar: Choose a large and wide jar with about 1/2 - 1 inch space (2-3 cm) below the lid.
Other recommended tools: small saucepan, cutting board, knife set
Prep ahead and storage: Pickled green onions should be made at least 2 hours before serving, but for best results make at least 24-48 hours ahead. Keep the jar refrigerated and it can be enjoyed for up to one month. Do not freeze.
Nutrition notes: Nutrition information is calculated with all brine ingredients (including full amount of sugar, salt, etc.), however the onions don’t absorb all of the liquid so the actual nutrition information is less than listed here.