To prepare 1kg of bellflower root, add salt and rub it to remove the bitterness.

Sweet and Sour Bellflower Root and Cucumber Salad
A recipe for a sweet and sour bellflower root and cucumber salad that removes the bitterness, has a crunchy texture, and doesn't release water, making it delicious even after being stored for a few days.
What You'll Need
Instructions
Rinse the bellflower root that has been salted and de-bittered with water, then drain.
Cut 3 cucumbers in half and slice them thinly on a bias.
Add salt to the sliced cucumbers to pickle them and drain the water.
Cut the water dropwort, 1 red chili pepper, and 3 Cheongyang chili peppers into bite-sized pieces.
In a bowl, mix the seasoning ingredients: 4 tbsp gochujang, 3 tbsp sugar, 1 tbsp minced garlic, plum extract, and 2 tbsp vinegar to make the sauce.
Mix the de-bittered bellflower root and drained cucumbers, then add the water dropwort and chili peppers.
Add the prepared sauce and toss gently so that the ingredients are well coated.