Boil 700ml of water for blanching mushrooms and watercress.

In a large pot, add 3 chicken thighs (or a whole chicken, cut into pieces) and cover with fresh water. Bring to a boil and cook for 20 minutes (longer if using a whole chicken). To check doneness, cut into the thickest part of the meat–there should be no pink flesh. Do not discard the broth–this will be the base of the soup.

Wash the mushrooms and watercress thoroughly. Tear or slice the mushrooms into bite-sized pieces. Cut off any tough stems from the watercress.

Blanch the mushrooms for 30 seconds, then remove them with a strainer. Using the same water, blanch the watercress for 30 seconds, then drain and set aside.

Remove the boiled chicken and let it cool slightly. Separate the meat from the bones and shred it into bite-sized pieces.

In a large bowl, mix shredded chicken, mushrooms, and watercress with gochugaru, minced garlic, soy sauce, salt, and black pepper. Toss well until evenly coated.

Bring the reserved chicken broth back to a boil. Add the seasoned mixture and let it simmer for 20 minutes over medium heat. Taste the soup and adjust with more salt or soy sauce if needed.

Ladle into bowls and serve hot. This soup pairs well with steamed rice and kimchi.