Combine ground pork, ginger, Shaoxing wine, and soy sauce in a small bowl. Mix well and set aside at room temperature to marinate for 10 minutes. Add the breadcrumbs and egg. Fold until it forms a quite soft paste. Add a bit more breadcrumbs if the paste is too runny. Do not over-mix.

Heat oil in a 3-quart pot over medium heat until hot. Add the garlic, ginger, and green onion. Stir a few times to release the fragrance.

Add kimchi. Cook and stir for 2 minutes or until tender

Add the Gochujang. Cook and stir for 1 minute, when the ingredients are evenly coated.

Add the chicken stock, tofu, sugar, and salt. Cook over medium high heat until bringing to a boil. Turn to medium low heat and simmer for 5 minutes.

Add the mushrooms and kale. Cook for 5 minutes.

Use a medium-sized spoon or small cookie scoop to scoop the ground pork, shape it into a ball, and add it into the soup. Continue making the rest of the meatballs one at a time, in the same manner. Cover and simmer for about 5 minutes, or until the meatballs are cooked through but still very soft. You can take out a meatball and cut it to check whether it’s cooked. Remove the pot from the stove.

Pour the stew into serving bowls and garnish with egg yolk, green onion, and sesame seeds, if using. Serve hot with steamed rice.