The root of this species (radix platycodi) is used extensively in as an anti-inflammatory in the treatment of coughs and colds. In Korea the plant is known as DoRaJi (도라지) and its root, either dried or fresh, is a popular ingredient in salads and traditional cuisine.
This has bitter taste, so you have to soak in water several hours (fresh one) or at least overnight (dried one) before you use them for cooking.
For Cold, Sidedishes, Soup, Salad, BiBimBap
Dried Bellflower roots: Keep in the cabinet. Long term storage: Keep in the freezer
Fresh Bellflower roots: Keep in the refrigerator