Rinse the cockles 2–3 times in cold water.

Boil water generously enough to submerge the cockles.

When the water boils, prepare 1 cup of cold water and add it in three intervals.

Add the cockles and stir in one direction while boiling.

Turn off the heat when the cockles start to open slightly.

Drain the cockles and let them cool naturally. Open any unopened shells using a spoon.

Remove the shells and prepare the cockle meat.

Mix gochujang, chili powder, minced garlic, soy sauce, vinegar, oligosaccharide, sugar, sesame oil, and sesame seeds to make the seasoning sauce.

Slice the onion, green chili, and cut the water dropwort into 4–5 cm lengths.

Combine the cockles, vegetables, and seasoning sauce in a bowl.

Cook the somen noodles and prepare them for serving.