Step 1

In a large pot, heat the olive oil over medium-high heat. Add the leeks and celery and saute until translucent, about 10 minutes. Add the garlic and ginger. Cook for another 5 minutes. Add the miso, garlic powder, and onion powder and cook for another 5 minutes.

Step 2

Add the vegetable broth, water, oyster mushrooms, carrots, bay leaves, lemongrass, tamari, lemon juice, vinegar, and kombu. Mix well. Bring to a boil and cook for 5 minutes. Reduce the heat to low and cook for another 30 minutes.

Step 3

Season with freshly ground black pepper and add the tofu, if desired. Discard the bay leaves and kombu and serve. Serve with scallions, sesame seeds, and/or red pepper flakes, if desired.