Peel and thinly slice or grate the fresh ginger to yield about 1 tablespoon. Mince 3 garlic cloves. Separate green onion whites from the greens and thinly slice both; reserve greens for garnish.

Build broth

In a large pot, heat sesame oil over medium heat until shimmering. Add the ginger, minced garlic and the white parts of the green onions. Sauté for 30–60 seconds until fragrant, stirring constantly to prevent burning.

Pour in 6 cups vegetable broth and 1 cup water. Stir in 2 tablespoons soy sauce and bring the mixture to a gentle simmer over medium-high heat.

Lower heat to maintain a gentle simmer. Stir in 2 tablespoons miso paste: scoop a small ladle of hot broth into a bowl, whisk the miso into that until smooth, then return the mixture to the pot. This prevents clumping and preserves miso probiotics.

Season the broth with 1 teaspoon salt and 1 teaspoon black pepper. Taste and adjust soy sauce or salt as needed.

Vegetables & Tofu

Prep tofu and vegetables

While the broth comes up to a simmer, press and drain the tofu if not already done. Cut into 1/2-inch cubes. Peel and slice the carrot on the bias, clean and slice shiitake mushrooms, and measure out spinach and corn.

Add carrots and shiitake mushrooms to the simmering broth first, since they take a bit longer to soften. Simmer for 4–5 minutes.

Gently add the cubed tofu to the pot and simmer another 3–4 minutes to heat through and allow flavors to meld.

Add frozen corn (if using) and spinach or chopped bok choy. Simmer 1–2 minutes until greens are wilted and corn is heated through.

Stir in thinly sliced green onion greens and remove the pot from heat.

Thickening & Finish

Finish soup

If you prefer a slightly thicker mouthfeel, whisk 1 teaspoon cornstarch into 2 tablespoons cold water to make a slurry. While the soup is gently simmering, slowly stir the slurry into the pot and simmer 1 minute until lightly thickened. Skip this step for a clear broth.

Adjust seasoning: add up to 1 teaspoon red pepper flakes for heat (optional), more soy sauce for saltiness, or a squeeze of lime for brightness.

Ladle soup into bowls. Garnish with reserved green onion greens and chopped cilantro or parsley. Serve with lime wedges on the side.