Sterilize two 1-quart canning jars (along with two canning lids and two rings) by washing them and then submerging them in boiling water for 5 minutes. Dry upside down on a clean cloth.
If the garlic scapes are tough, blanch them for a couple minutes in salted water, then plunge into an ice-water bath. This will tenderize them.
In a saucepan, bring the ginger, water, rice wine vinegar, mirin, sugar and salt to a boil. Remove from heat. Taste and adjust flavors—sour, sweet, salty—to preference. Drop in the kombu and let sit for 10 minutes.
Meanwhile, crush the shiso leaves with your fingers and drop two into each jar. Stuff in the cold garlic scapes. Remove the kombu and ginger from the saucepan and drop them evenly into the jars.
Finish by evenly distributing the brine between the jars. Seal and let sit overnight before refrigerating. Although a week is sufficient for pickling, the flavor of the subtle kombu and shiso will intensify after a couple months. To serve, either eat the pickled scapes whole, or chop and toss them with rice, salads, or any dish of your choosing.
— Recipe and photo by Brian Fink, The Cascadian Kitchen