This comforting Korean soft tofu stew (Sundubu Jjigae) is simple to make and deeply satisfying. Combining soft tofu, spices, and mushrooms with a broth made from kombu seaweed and shiitake mushrooms, this stew is pure comfort in a bowl!
Prepare the broth by combining the dried shiitake mushrooms and kombu with 3 cups of water, refrigerate overnight. If short on time, cover with hot water and steep for at least 1 hour. Remove and discard the kombu and strain the broth, reserving the liquid. Slice the rehydrated shiitake mushrooms and set aside.
Warm both oils in a large pot over medium heat. Add the yellow and white parts of the green onions and sauté for 2–3 minutes until fragrant. Reduce the heat to low, then the green onions and sauté for 2–3 minutes until fragrant. Reduce the heat to low, then add the gochugaru and stir gently for 20–30 seconds until the oil turns red and aromatic, being careful not to let it burn.
Add the garlic and sauté for about 1–2 minutes until fragrant. Stir in the chopped kimchi, kimchi juice, sliced shiitake mushrooms, and soy sauce, then cook for a few minutes to combine the flavors.
Pour in the prepared broth and stir well. Cover and bring to a strong simmer. Add the zucchini and continue cooking for about 10 minutes, or until the zucchini begins to soften. If using, add in the cornstarch slurry and mix well. Allow the soup to continue cooking for a few minutes to thicken slightly.
Gently add the soft tofu in large slices or spoonfuls, keeping the curds intact rather than breaking them apart. Add the enoki or shimeji mushrooms. Bring the stew to a gentle boil and let it cook for a few more minutes until everything is heated through.
Ladle the stew into bowls and serve hot, garnish with sliced green onions and additional kimchi if desired.