"My good friend Suzette makes the most unusual yam and red lentil soup," Earthbound consulting chef Pam McKinstry says. "And it's so good that I begged her to share the recipe!" And here it is. The origins of this silky soup are lost in time — but whatever the original inspiration, Suzette has given it an Asian flair that makes it memorable.
Old World yams and New World sweet potatoes are indeed different vegetables. In the US today, the terms are often used interchangeably to describe popular varieties of red-skinned, orange-fleshed tubers with pointed ends. At Earthbound Farm we produce the Garnet and Jewel varieties, which are commonly called yams but are actually sweet potatoes. No matter what you call them, though, they're delicious!
Heat the oil in a large pot over medium heat and add the onion. Cook, stirring frequently, until the onion softens, about 5 minutes. Add the garlic and curry paste and cook for 1 minute, stirring constantly.
Add the broth, yams, lentils, coconut milk, fish sauce and sugar, and raise the heat to high. Bring the soup to a boil, then reduce the heat to medium-low, cover the pan and simmer until the yams and lentils are soft, 30 to 40 minutes.
Let the mixture cool for 10 minutes, then purée it in batches in a food processor or blender. Return the soup to the pot, add the lime juice and reheat over low heat. If the soup is very thick, thin it to your desired consistency with a little hot water. Divide among warm bowls and garnish each serving with a sprinkling of basil or cilantro, if you like.