Wash the cucumber thoroughly and peel off only the spiky parts using a peeler. Slice it diagonally.

Cut the diagonally sliced cucumber pieces in half lengthwise.

Slice 1/2 onion into thick strips and mix with 1 tbsp salt. Let it sit for 20 minutes.

Rinse the salted cucumber and onion under water and drain.

Use a kitchen towel or gauze to remove as much water as possible from the vegetables.

Place the vegetables in a bowl and mix with 2 tbsp chili powder to add color.

Combine 1 tbsp soy sauce, 2 tbsp vinegar, 1/2 tbsp sugar, 1 tbsp plum extract, 1/2 tbsp minced garlic, and 1 tbsp ground sesame seeds. Add this mixture to the vegetables and mix well.