Cut root end off Brussel sprouts and pluck off as many leaves as possible. Cut the center rib/leaves in half. Place leaves and rib into a large bowl with daikon radish and carrots.
Add 1 cup cold water and ¼ cup kosher salt. Mix well with your hands to combine. Set aside for 10 minutes. Rinse the mixture under cold water and drain.
Mix the kimchi paste into the vegetable mixture thoroughly.
Put the kimchi into an airtight container, glass jelly jar, or plastic bag.
Press the top of the kimchi down with your hands to protect your kimchi from being exposed to too much air.