Curried sweet potato and lentil soup, made with red lentils and curry paste, packs a wallop of that traditional Thai juxtaposition of sweet, sour, salty, and hot even though it’s not at all southeast Asian in origin.
This curried sweet potato and lentil soup recipe is, as the author says, adept at balancing the spiciness of red curry paste with the sweetness of sweet potatoes and the tanginess of lime such that all the individual flavors explode. In other words, it draws on all the requisite hot, sour, salty, sweet components of southeast Asian fare that make things taste so incredibly complex…and yet with very few ingredients and little effort. A “beautiful bowl of deliciousness” is how one of our testers describes it. We ain’t arguing.–Angie Zoobkoff
☞ Like soup recipes? Try these:
- Corn and Roasted Poblano Soup
- Yellow Pea and Coconut Milk Soup
- Roasted Carrot Soup with Cilantro and Mint Relish
- Italian Kale Soup ~ Zuppa Valdostana
☞ Table of Contents
Curried Sweet Potato and Lentil Soup
- 18 ounces sweet potatoes (1 to 2 sweet potatoes)
- 2 cups (12 oz) red split lentils
- 1 to 2 teaspoons mild olive or vegetable oil
- 1 1/2 to 3 tablespoons red curry paste
- 6 1/2 cups stock (whether beef stock or chicken stock or vegetable stock) plus more as needed
- Juice of 2 limes (3 to 4 tablespoons)
- Coarse black pepper
- Sea salt flakes
- Cilantro, crushed peanuts, or coconut milk for garnish (optional)
- Peel the sweet potatoes and chop them into 1/2-inch (1-cm) dice.
- Rinse the lentils in a sieve under cold running water until the water runs clear.
- Heat a large saucepan or pot—one that has a lid— over medium-high heat. Add the oil and red curry paste and stir-fry just until it becomes strongly aromatic, about 1 minute. If you like things with just a mild heat, add just 1 1/2 tablespoons red curry paste. If you like things hotter, opt for 2 to 3 tablespoons red curry paste.
- Add the potato and lentils and stir to coat them with the paste. Pour in the stock and bring everything to a boil. Reduce the heat to a very gentle simmer, cover, and gently simmer just until the lentils and sweet potato are soft, 25 to 35 minutes. Remove from the heat.
- If using a blender or food processor, let the soup cool for at least 10 minutes and then carefully ladle it into a food processor and blitz until smooth, working in batches if necessary. The soup will be quite thick. If a thinner soup is desired, add stock. Return the soup to the pan and, if needed, rewarm over low heat. If using an immersion or stick blender, stick the blender straight in the pot and puree until smooth. If a thinner soup is desired, add stock. If needed, rewarm over low heat.
- Add a generous pinch of pepper and the lime juice to the soup and stir to combine. Serve immediately and, if desired, garnish with cilantro, peanuts, or a drizzle of coconut milk. Serve immediately. (As with most soups, this freezes just fine in an airtight container or portioned in individual servings in resealable plastic bags. Defrost and rewarm over low heat before serving. Keep in mind that the soup will thicken in the fridge or freezer, so you’ll need to add more stock or water when rewarming it to attain the original consistency.)
Recipe Testers’ Reviews
Wow! This curried sweet potato and lentil soup recipe is a keeper. Creamy and rich with just enough heat to make it interesting, it’s a beautiful bowl of deliciousness. It’s hard to believe there’s no dairy, no fat, no thickener—just the sweetness from the potatoes, the lovely creaminess from the lentils, the spiciness from the red curry paste, and the brightness from the fresh lime juice. A brilliant combination of flavors that hits all the Thai flavor profiles—spicy, sweet, hot, sour—yet feels very homey and familiar.
This soup would be equally at home beside samosas for a light dinner, as a side with an all-American grilled cheese sandwich for lunch, or as a starter to a Thanksgiving dinner. This was a snap to put together and ready to serve in under an hour from start to finish. I topped it with some crispy fried shallots to add a little crunchy contrast to the smoothness and served it with additional lime wedges. It was even better reheated the next day—as so many soups are! My limes were nice and juicy and yielded 1/2 cup lime juice. I wouldn’t use less as the soup is very rich.
I’ve been wanting to cook more soups with sweet potatoes and lentils because I am looking for healthier but still flavorful alternatives for dinner recipes to serve for my family. I’m thrilled at how delicious simple it is to make this curried sweet potato and lentil soup. It took less than 10 minutes to prep the ingredients and throw them in a pot. The flavors are sweet from the potatoes and tangy from the lime juice with a spicy warm kick from the curry paste. My family loved this soup!
I made this soup in the heat of the summer and I can only imagine how comforting this soup would be on a blustery day. I used store-bought Thai red curry paste but when I have more time I’m anxious to try my hand at making my own curry paste. I loved the final touch of adding freshly ground pepper and lime juice after blending the soup, it really did bring out the wonderful flavors. I will definitely make this again and next time I may even blend it a bit less or just blend half the amount to leave some of the cubed potatoes and lentils whole to create slightly chunkier soup.
This recipe is more than the sum of its parts. It’s soooo simple and soooo easy. And you can make it even easier by making it in a slow cooker or a pressure cooker and using a stick blender to purée it right in the cooking vessel. I went the pressure cooker route, and if you have a pressure cooker, I highly recommend you do the same for an insanely easy weeknight dish. I also deviated a bit by adding a small amount of oil to the pot to keep the curry paste from scorching or sticking. In my electric pressure cooker, I cooked this for 12 minutes on high and then allowed a natural pressure release. If you want to dress this recipe, it would be easy to add a cilantro garnish or a swirl of coconut milk. But for the effort, it’s a winner just as it is.
This curried sweet potato and lentil soup is a very easy, flavorful soup with a nice kick and great color. I used only 1 1/2 tablespoons curry paste and that was plenty spicy for our taste. We had Indian papadums with it.
This curried sweet potato and lentil soup is a beautiful and warmly spiced soup. I expected it to have a “burn your mouth” heat with the amount of curry paste used (I added 3 tablespoons) but was pleasantly surprised to find it warmly spiced but not overly so.
I used a homemade chicken stock. The paste really only took a minute to become aromatic and the soup simmered for 45 minutes total for everything to become soft and tender. Rather than dirty up another appliance, I used an immersion blender to puree the soup, which worked really well.
We got about 10 servings for our first course but this could be more or less depending on the size of your servings. We found a dollop of crème fraîche and an extra squeeze of lime brought this over the top. Certainly this is going to be on the roster for winter dinners.
This curried sweet potato and lentil soup was delicious, especially when the lime was added. The timing on everything was accurate, from when the curry became aromatic to how long it took the lentils and potatoes to become soft.
Originally published December 06, 2020