Rinse cucumbers. Cut off both ends. If using long Korean cucumbers, cut in half (or thirds if long) crosswise.
Add 6 cups of water with 1/2 cup of salt in a medium size pot. Bring it to a boil. Turn the heat off. Pour the boiling water over the cucumbers in a bowl. Keep the cucumbers submerged by weighing them down with a bowl or plate. Let it sit until the cucumbers are bendable, about an hour or two, depending on your cucumbers and salt.
Meanwhile, cut the chives into 1/2 inch lengths. Julienne the radish (or onion), and then cut into the same lengths.
Combine all the stuffing ingredients along with 1/4 cup of water, and mix well. It should taste a bit salty.
Drain the cucumbers. Holding the top end of the cucumber on the cutting board, run a small knife through the middle lengthwise. Leave 1/2 inch uncut at both ends. Turn the cucumber and make another cut through the middle lengthwise to make a cross cut, again leaving 1/2 inch uncut at both ends. Repeat with all the cucumbers.
Gently open each slit and insert about a teaspoonful or two of the stuffing. Be sure to fill all 4 slits of each cucumber. Repeat until all the cucumbers are stuffed. Place them in a jar or an airtight container. Leave it out at room temperature for a day. Then, store in the fridge.
This cucumber kimchi can be eaten right away but will taste better after a day or two in the fridge. It will keep well for a couple of weeks.Originally posted in August 2012 and updated here with an improved recipe and new photos.