White Sweet Potato Soup
with Pickled Scallions
We’re crazy for little white sweet potatoes—they’re starchier and drier than the orange-fleshed variety, giving them a dense texture that we love. They also make such a silky-smooth soup. Japanese in its inspiration, this soup is a perfect foil for the pickled scallions.
1 small clove garlic, finely grated or minced
¼ cup rice wine vinegar
¼ cup extra-virgin olive oil
1 teaspoon Asian sesame oil
1 large hand of fresh ginger (about 6 ounces),
unpeeled, coarsely chopped
6 cups chicken or turkey broth
2 pounds small white sweet potatoes
Chop 1 bunch of the scallions and put them in a small bowl. Add the garlic. Stir in the vinegar, olive oil, and sesame oil and season with salt. Set aside to pickle.
Coarsely chop the remaining 2 bunches of scallions and put them with the ginger in a medium pot. Add the broth and gently boil over medium heat for 30 minutes. Strain the broth through a fine-mesh sieve, return it to the pot, and keep warm over low heat.
Put the unpeeled potatoes in a medium pot of cold water and add a pinch of salt. Boil over medium heat until tender, 15–20 minutes. Drain and peel the potatoes. Drop them into a blender or food processor. Purée the potatoes with 5 cups of the broth until very smooth, thinning it with more broth if needed. Serve in warm bowls with a spoonful of the pickled scallions floating on top. Garnish with a few tiny nasturtium leaves if you have any on hand.