Shiitake, Sweet Potato, and Tofu Soup with Miso

1. Cook Vegetables

Start by heating 1½ tablespoons of toasted sesame oil in a large pot over medium heat. Add the cubed sweet potatoes, sliced scallion whites, most of the scallion greens, shiitake mushrooms, and ginger coins, along with a pinch of salt. Stir these ingredients together, allowing the vegetables to cook for about 5 to 7 minutes.

2. Simmer with Stock and Kombu

Once the vegetables are starting to soften, raise the heat to high and pour in the vegetable stock, along with an additional teaspoon of salt and the kombu, if using. Let the soup come to a rolling boil, then reduce the heat to a gentle simmer and let it cook for another 10 to 15 minutes.

3. Prepare and Add Miso

After the soup has simmered, carefully remove the kombu with tongs or a fork. If you'd like, chop the kombu into small pieces and set aside. In a separate bowl, whisk the miso with a bit of the hot soup broth until smooth, then return this mixture to the pot.

4. Add Spinach and Tofu

Next, add the torn spinach, cubed tofu, and chopped kombu (if using) to the pot. Stir gently until the spinach wilts, which should take just a minute or so.

5. Season and Serve

Finally, taste your soup and adjust the seasoning with more miso or salt, as needed. Ladle the soup into serving bowls, and garnish with the reserved scallion greens and a drizzle of toasted sesame oil for an extra touch of flavor.