Creamy, colorful, and full of flavor, this roasted sweet potato and red pepper soup is an easy vegan recipe you need to add to your rotation! It features healthy, Thai-inspired ingredients, such as coconut milk, lemongrass, cilantro, and peanuts. Every spoonful will captivate your senses and keep you coming back for more!
Adding coconut milk to soups is one of my favorite hacks. First, its creaminess is unmatched. Period. Plus, it’s the ideal complement to a little spice and a touch of acid, two things you’ll find in this sweet potato and red pepper soup!
Not only is every spoonful of this recipe a creamy, coconut-infused flavor bomb, the vibrant color can brighten just about any dreary, cold day. The veggies provide a beautiful hue while packing lots of fiber and micronutrients.
Last but not least, this interesting soup features lemongrass! If you’re not familiar with this herb, it adds a mild citrusy and sweet flavor. I’ve documented how to prepare lemongrass for cooking in the post, so be sure to check it out while you scroll.
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Ingredients and Substitutions
- Sweet potatoes and red peppers: Technically you can use yellow or orange bell peppers if that’s all you have, but roasted red peppers have the deepest and sweetest flavor in my opinion.
- Onion: Use a yellow onion if you have it, but any kind will work as a sub.
- Garlic: Fresh garlic adds the most potent flavor, but you can use garlic powder or dried garlic.
- Curry powder: Use mild curry powder if you don’t want too much spice. For a spicy sweet potato and red pepper soup, use a powder with more heat or even a curry paste.
- Lemongrass: Many grocery stores sell fresh lemongrass stalks in the produce section by the packaged herbs or containers of already prepared lemongrass batons. If you can’t find fresh lemongrass, look for lemongrass paste. This is typically sold in a tube or a jar by the other herbs. Use 1 to 2 teaspoons in place of the fresh stalks in this recipe.
- Coconut milk: Use the full-fat, unsweetened kind that comes in a can for maximum creaminess. I like Thai kitchen brand.
- Vegetable stock: Sub chicken stock if you don’t need the soup to be vegetarian/vegan.
- Cilantro: Omit or sub another fresh herb for garnish.
- Peanuts: I like to use dry roasted peanuts (unsalted or salted) as a garnish. Sub another nut if desired.
Instructions
The full recipe card for sweet potato and red pepper soup is at the bottom of the post. Here’s a preview of the steps with photos to guide you.
Roast the sweet potatoes and red peppers with olive oil until tender and lightly browned.
While the veggies roast, cook the onion in olive oil in a soup pot until softened. Add the garlic and curry powder and cook until fragrant.
Add the coconut milk, vegetable broth, and lemongrass batons. Bring to a boil, then cover and reduce heat to medium-low. Simmer while the veggies finish roasting.
Remove the lemongrass batons. Add the roasted veggies. Blend until smooth.
How to Prep Lemongrass for Soups
Follow these steps for prepping lemongrass batons that you can simmer in broth to add flavor. This is my preferred way of using lemongrass in sweet potato and red pepper soup. Some people like to cut it into pieces and blend it into the soup, but I find it to be very fibrous and prefer to extract the flavor through simmering and then remove before eating.
Slice off the root end about ½-inch from the bottom. Cut off the top of the stalks where the layers split apart.
Remove the dry outer layer from the remaining portion of the stalks. You may have to remove 2 layers if it’s very dry.
The remaining sections will be pliable and feel and look fresh. Cut these into 3-inch batons.
Use the back of a chef’s knife, or a meat tenderizer if you have one, to smash the batons to release the aroma and oils.
Storage and Reheating
Sweet potato and red pepper soup tastes even better with age! Keep leftovers in an airtight container in the fridge for up to 3 to 5 days. Reheat in a saucepan or small pot over medium heat, stirring occasionally, until warmed through.
This recipe also freezes beautifully. Let it cool completely, then transfer to freezer-safe containers. Leave about an inch of headspace, seal tightly, and freeze for up to 3 months. Thaw in the fridge overnight before reheating or warm straight from frozen. Just be sure to warm frozen soup in a pot with a lid and stir frequently to prevent scorching.
Similar Recipes
Love this Thai-inspired sweet potato and red pepper soup? Check out these other dishes while you’re here:
📖 Recipe
Sweet Potato and Red Pepper Soup
Equipment
- Handheld blender (immersion blender)
Ingredients
- 2 tablespoons extra virgin olive oil - divided
- 1 large sweet potato - about 1 pound, peeled and cut into 1-inch cubes
- 2 medium red bell peppers - about 1 pound, deseeded and cut into 1-inch pieces
- ½ teaspoon salt - divided
- 1 small yellow onion - diced, about 1.5 cups
- 3 cloves garlic - minced
- 2 teaspoons mild curry powder - use a spicier powder or curry paste for more heat
- 2 lemongrass stalks - cut into 6 small batons and smashed, see instructions
- 2 cups vegetable broth
- 14 ounces coconut milk - full-fat, canned
- 3 tablespoons chopped fresh cilantro - for garnish
- 3 tablespoons roughly chopped peanuts - for garnish
Instructions
- Preheat the oven to 400 degrees F/204 degrees C. Line a baking sheet with parchment paper and set aside.
- Prep the lemongrass stalks if they did not already come sliced in batons. Trim about ½-inch off the root ends. Then, trim off the top area of the stalks where the leaves come apart. This is usually the top 2 inches.Remove the tough outer layer of what's left of the stalks. You may need to remove 2 layers, depending on the freshness. You'll be left with 2 pliable and fresh-smelling pieces that are about 6 to 9 inches long each. Cut each piece into 3-inch batons. For 2 lemongrass stalks, you should get 4 to 6 batons. Finally, use the back of a chef's knife or a meat tenderizer if you have it and smash the batons to release the oils and aroma.
- Transfer the sweet potato and red pepper to the baking sheet. Toss with a tablespoon of the olive oil and ¼ teaspoon of the salt. Spread out in a single layer.
- Roast the vegetables on the center rack of the oven for 25 to 35 minutes, flipping halfway through, until tender and lightly browned.
- While the veggies roast, prepare and simmer the broth. Warm the other tablespoon of olive oil in a large soup pot or Dutch oven. Add the onion and cook for about 5 minutes until softened. Stir in the garlic, curry powder, and rest of the salt. Cook for another minute until fragrant.
- Put the lemongrass batons, vegetable broth, and coconut milk in the pot. Increase heat to bring to a boil, then reduce heat to maintain a simmer. Cover and let the broth simmer, stirring occasionally, while the veggies finish roasting.
- Once the veggies are done, remove the lemongrass batons from the broth. Add the veggies to the pot and remove from heat. If you have a handheld blender, puree the soup right in the pot until smooth. See notes for upright blender instructions.
- Serve warm, garnished with cilantro and peanuts. Enjoy!
- Leave a rating or review by tapping the stars on this recipe card (above) or in the comments section (at the end of the post)!
Notes
- Upright blender instructions: Transfer the soup in batches. Leave the lid cracked or remove the plastic circle in the center and cover it loosely with a dish towel to let steam escape. Blend until smooth, pour into a large bowl, and repeat with the rest of the soup until it’s all blended.
- Storage: Keep leftovers in an airtight container in the fridge for 3 to 5 days. Reheat in a saucepan or pot, stirring frequently, over medium heat until warmed through. This soup also freezes beautifully and will last for 3 months in the freezer. Thaw before reheating or, if heating from frozen, use a pan or pot with a lid and stir frequently to prevent scorching.
- Subs: If you can’t find fresh lemongrass, see if your store sells lemongrass paste in a tube or jar. Use 1 to 2 teaspoons of that in place of the fresh stalks in this recipe.
Art
The recipe brought me back to my youth when mom prepared this for her family. It will be a keeper for us.
Lizzie Streit, MS, RDN
Hi Art, I’m so glad this was a nostalgic recipe for you and that you enjoyed it! Thanks for your 5-star review.