1.Peel the 2 kg chonggakmu but keep the green stems attached. Cut off the tails and remove the dead leaves.
2.Cut the radishes in half lengthwise. Grab the 2 halves with both hands, split the greens, and put them into a large basin.
3.Add some cold water to the radishes in the basin, and then drain.
4.Sprinkle the radishes with 0.5 cup kosher salt and mix with your hands. Let it sit in the salt for .
5.Turn over the radishes so they salt evenly and let it sit for another .
6.Wash the radishes thoroughly about 4-5 times to remove any dirt and excess salt, and drain in a colander.
7.Mix 0.25 cup flour and 2 cups water in a pot and heat over medium heat.
8.Keep stirring until it thickens. When you see some bubbles, add 2 tbsp sugar and stir for before removing from the heat. Cool it down.
9.Mince 12 cloves garlic and 0.5 medium onion. Chop 5 stalks green onions. Set aside.
10.Transfer the porridge to a large mixing bowl.
11.Add the minced garlic and onion, 1 cup gochugaru, 0.25 cup fish sauce, and the chopped green onions. Mix well.
12.Add the ponytail radishes and mix well with your hands.
13.You can eat it right after making it, but this kimchi is more tasty when it ferments. Transfer the kimchi to a glass jar or plastic container and keep it at room temperature for a couple of days.
14.When the kimchi ferments, scoop some kimchi juice from the bottom of the container to the top so that the top layer of the kimchi won't dry out and your kimchi will be juicy.