Step 1

Bring a large pot of water to a boil. Meanwhile, in a large bowl, whisk together the gochujang, vinegar, soy sauce, sugar, sesame oil, 1 tablespoon sesame seeds and the kimchi juice. Set aside.

Step 2

Thinly slice the cucumber on the diagonal. Stack several slices and cut lengthwise into matchsticks. Repeat with the remaining slices. Set aside.

Step 3

Add the noodles to the boiling water and cook, stirring frequently, until tender, about 2 minutes. Drain in a colander, then add 1 cup ice cubes on top. Rinse the noodles under cold running water, tossing constantly, until completely cool to the touch. Remove any unmelted ice cubes, then drain well.

Step 4

Add the drained noodles to the gochujang mixture, along with the kimchi. Toss, then taste and season with salt and additional vinegar. Transfer to a shallow serving bowl, then mound the scallions and cucumber on top. Sprinkle with the remaining 1 tablespoon sesame seeds. Tossing just before serving.