Toast the sesame seeds in a non-oiled pan over medium heat for 3-4 minutes, stirring occasionally, until fragrant and lightly browned.
Peel the kohlrabi and cut into very fine strips.
Sprinkle the kohlrabi strips evenly with salt and place in a sieve. Let sit for 20 minutes.
Rinse the kohlrabi with cold water and squeeze well to remove excess moisture, or spin dry.
Chop or grate the garlic clove very finely. Cut the chives into short pieces.
In a small bowl, combine the sesame oil, lemon juice, Korean chili powder, apple cider vinegar, and sugar. Stir until the sugar dissolves.
In a large bowl, combine the kohlrabi, garlic, toasted sesame seeds, chives, and dressing. Mix well. Cover and refrigerate for at least a few hours, or preferably overnight.