Wash all three cucumbers and skin each cucumber with a peeler. Do not peel-off all of the skin, rather make uneven peels.
Cut Asian Chives into small bite-sized pieces (optional)
Chop cucumbers into half inch circles.
Sprinkle 4-5 big pinches of kosher salt onto the cucumber slices and give them a good mix with your hands. Set the cucumbers aside for 30 minutes and they will slowly release water. After 30 minutes, check that they can bend without snapping. Then thoroughly rinse off all the salt under running water and let them drip off excess water.
For the marinade: Thoroughly mix Vinegar (3 teaspoons), Gochugaru (2.5 teaspoons), Sugar (2.5 teaspoons), Soy Sauce (1 teaspoon), Minced Garlic (1 teaspoon) and Sesame Oil (1 teaspoon), Sesame Seeds (few shakes).
Dress the cucumbers (and asian chives) in the marinade. Get in there with you hands and coat all of it!