Ingredients 1 quart water 1 small onion, coarsely chopped 2 garlic cloves, coarsely chopped 1 tablespoon coarsely chopped peeled fresh ginger 1 stalk of fresh lemongrass, thinly sliced crosswise One 1/2-pound sweet potato, peeled and cut into 2-inch cubes 1/2 teaspoon sambal oelek or other Asian hot sauce Salt 1/2 tablespoon chopped cilantro Lime wedge, for serving Instructions In a saucepan, bring the water to a boil with the onion, garlic, ginger, lemongrass and sweet potato. Cover and simmer for 25 minutes until the potato is tender. Transfer the sweet potato to a blender. Strain the broth; add 1 cup to the blender and reserve the rest for another use. Puree the sweet potato soup. Return the soup to the saucepan. Stir in the sambal oelek, season with salt and simmer until heated through. Pour the soup into a bowl, top with the cilantro and serve with the lime wedge.