Slice 1/2 onion thinly and set aside.

Scrub 3 cucumbers with coarse salt, rinse, and slice diagonally into 0.5 cm pieces.

Sprinkle 1/2 tbsp coarse salt over the cucumber slices and let sit for 5 minutes.

Rinse the salted cucumbers 1-2 times in cold water and drain well.

In a large bowl, combine cucumbers and sliced onions.

Add 1 tbsp soy sauce, 3 tbsp vinegar, 1 tbsp plum extract, 1 tbsp oligo syrup, 1 tbsp sugar, 1 tbsp minced garlic, 1 tbsp sesame oil, 2 tbsp chili powder, 2 tbsp gochujang, and 1 tbsp sesame seeds.