Trim or snap the ends of 1 bunch of asparagus and wash the spears. Cut the spears in half if necessary to fit in a one-quart canning jar. Divide the spears between two canning jars, standing upright.
In a medium saucepan, bring 3 3/4 C. water to a simmer with 3 C. white wine vinegar, the zest of 1 lemon, 1 1/2 t. coriander seeds, 2 bay leaves, 2 T. salt and 3 T. sugar. (If you like your pickles really tart, you can reduce the amount of sugar)
Trim the bases of 1 bunch spring onions and remove any dried leaves or skin. Cut any fat ones in halves or quarters lengthwise. Then cut them in half lengthwise.
Add to the pan and simmer for 4 minutes.
Divide the onions between the two jars, then fill each jar with cooking liquid. Place a lid on the jars and loosely tighten, then let sit for one hour at room temperature.
Tighten the lids completely and refrigerate for at least one day before eating. The pickles will keep for a month in the fridge.