Sweet Potato Ramen Noodle Soup in Silky Sesame Broth
Makes 4 large servings
Japanese ramen noodle soups are insanely popular, but typically loaded with off limits animal products. The broth can vary widely depending on where it hails from, but this opaque, creamy colored broth imitates the some of the richer style of ramen broths with help from miso and smoky, nutty tahini. The elaborate toppings, including unconventional roasted sweet potato, really make the soup special, so consider preparing the sweet potato and corn in advance and gently heating before serving to help spread out the preparation. Ramen noodles are not even essential for the enjoyment of this soup; easy to find udon noodles work just as well, or for a heartier soup use buckwheat soba noodles.
Ingredient tip: Japanese sweet potatoes, also known as satsuma-imo, typically have a reddish skin and pale yellow flesh. They’re sweeter and drier in texture than American orange sweet potatoes, which can be substituted for these in this dish; American sweet potatoes may require a little extra baking time, about 4 to 6 minutes.
4 teaspoons vegetable oil, divided in half
1 1/2 pounds Japanese sweet potato (satsuma-imo), scrubbed and diced into 1/2 inch cubes
2 cups corn kernels
1 cup finely shredded green cabbage
4 scallions, root ends trimmed and sliced paper thin
4 teaspoons toasted sesame seeds
4 tablespoons pickled ginger slices, sliced into thinnest shreds possible
1 sheet toasted nori seaweed, cut into 1/2 inch wide strips
Wasabi paste, as desired
Noodles and soup
10 ounces dry ramen noodles, dry udon noodles or dry buckwheat soba noodles
2 teaspoons toasted sesame oil
6 dried shiitke mushrooms
2 cups boiling water
4 cloves garlic, peeled and minced
1 large yellow onion, peeled and sliced into 1/4 inch wide half moons
2 three inch pieces kombu seaweed
6 cups water
1 pound silken tofu, sliced into 1/4 inch cubes (see page XX for slicing tips)
1/4 cup soy sauce
3 tablespoons mirin cooking wine
⅔ cup white miso paste, such as shiro miso
1/3 cup sesame tahini
4 cups spinach leaves or roughly chopped bok choy leaves
1. Prepare the soup toppings first: preheat oven to 400 degrees F and line a baking sheet with parchment paper. Toss sweet potato cubes with half of oil, spread in an even layer on the baking sheet and roast for 22 to 24 minutes, stirring pieces occasionally until sweet potato is tender. Turn off oven and keep sweet potato warm. Preheat the remaining oil in a stainless steel skillet over medium heat, add the corn and saute for 3 minutes or until corn is tender, then remove from heat and set aside. Keep the nori seaweed strips away from wet ingredients until it’s serving time.
2. In a large 3 quart soup pot bring water and salt to a rolling boil; slide in noodles and cook for 8 minutes or until tender but still firm (al dente). Drain and rinse well with cold water, then toss with sesame oil. In a mixing bowl cover dried shiitaki mushrooms with 2 cups of boiling water and let stand for 20 minutes or until tender. Remove the mushrooms, discard any hard stems and slice into very thin strips. Strain the mushroom soaking liquid through cheesecloth or a fine metal mesh sieve to remove any grit and set aside.
3. In a large 4 quart soup pot preheat the oil over medium heat, add the onion and fry for 4 minutes or until the onion is soft and translucent. Add garlic and chopped white part of the scallions and fry for another minute, then pour in the 6 cups of water and reserved mushroom soaking liquid. Add the kombu strip, increase heat to high and bring soup to a boil. Reduce heat to low and bring the soup to gentle simmer, then stir in sliced mushrooms, tofu, soy sauce, and mirin. Cover and simmer for 5 minutes.
4. Scoop the miso and the tahini into a mixing bowl and stir in 1 cup of hot broth. Use a rubber spatula to stir the broth into the miso and tahini to form a smooth sauce and stir this back into the soup. Stir in the spinach or bok choy leaves and continue to simmer until the leaves are wilted and tender, about 2 to 4 minutes. Turn off the heat and keep the soup covered. Remove and discard the kombu strip before serving the soup.
5. Divide the noodles into large, deep serving bowls. Ladle the soup on top of the noodles, making sure to distribute plenty of tofu, spinach and mushrooms along with lots of broth in each bowl. Top each soup with a handful of roasted sweet potato cubes, 1/2 cup corn kernels, and a 1/4 cup green cabbage shreds. Scatter on top of this 1 chopped scallion, 1 teaspoon sesame seeds, 1 tablespoon sliced pickled ginger, and a quarter of the nori seaweed shreds. Serve with wasabi paste for diners to stir into their soup as desired.
Serve each bowl of soup right away with both chopsticks and big wide soup spoons.