Boil 600ml water in a pot and add the broth tea bag. Let it simmer until the broth is flavorful, then remove the tea bag.

Prepare the vegetables: slice the onion, potato, and shiitake mushrooms; mince the garlic; and chop the green onion.

Add the minced garlic to the boiling broth and let it simmer for a few minutes.

Add the sliced potato to the broth and cook until tender.

Add the sliced shiitake mushrooms and onion to the pot and continue simmering.

Add the soft tofu to the pot, breaking it into smaller chunks, and simmer for a few more minutes.

Add the chopped green onion and perilla seed powder to the stew, stirring gently.