Soups, Stews & Chili

Hearty Red Lentil and Sweet Potato Soup

By Clara ·
November 1, 2026

When the onion and carrot soften in olive oil, the pot starts smelling warm and sweet before the spices even go in. A quick stir with cumin, coriander, and smoked paprika wakes them up, and the whole soup gets its character from that small, fragrant start. This hearty red lentil and sweet potato soup cooks in one pot, with dried lentils and sweet potato turning a simple broth into a filling meal.

I like the way the ingredients finish at different textures: the red lentils soften into the broth while the sweet potato stays in tender cubes. Cutting the potato into even 1/2-inch pieces helps it cook through alongside the lentils, and a little lemon juice at the end keeps the earthy spices from feeling heavy. The bowl is thick, gently spiced, and brightened just enough to make each spoonful taste balanced.

Why the Lentils and Sweet Potato Don’t Need to Be Blended

A thick soup doesn’t have to be smooth to feel hearty. Here, red lentils soften enough to give the broth body, while the sweet potato pieces bring a separate, tender bite. That contrast is what makes each spoonful feel substantial without turning the pot into purée. Keep the cubes close in size so they cook at a similar pace; oversized pieces can still be firm when the lentils have already broken down.

The soup also thickens as it cooks, so don’t judge its final consistency while the broth is just coming to a boil. Give the lentils time to soften at a gentle simmer, then stir in the lemon juice after the heat has done its work. That order keeps the finish fresh and lets the sweet, earthy ingredients stay in balance. If you prefer a looser bowl, you can adjust the texture when serving rather than rushing the simmer or changing the lentil-to-broth balance.

Why Red Lentils, Sweet Potato, and Lemon Belong in This Pot

• Dried red lentils — Choose dried split red lentils for this cooking time, and rinse and drain them before they go into the pot. They don’t need soaking. Older packages can take longer to soften, so use the tenderness of the lentils, not the clock alone, as your final cue.
• Sweet potato — A firm, unblemished potato is easiest to peel and cut cleanly. Keep the pieces even so some don’t collapse while others are still firm. Butternut squash is a workable swap if you want a less sweet, slightly firmer bite.
• Vegetable broth — Low-sodium broth gives you room to season the soup without having the salt level dictated by the carton. A good everyday broth works well; choose one with a clean vegetable taste rather than a heavily seasoned one.
• Cumin, coriander, and smoked paprika — Ground spices lose aroma over time, so use jars that still smell distinct when you open them. Smoked paprika gives the soup its smoky note; regular sweet paprika will keep the color but leave out that smokiness.
• Fresh lemon juice — Fresh juice tastes brighter here than bottled and takes only a moment to squeeze. Stir it in at the end, once the lentils and sweet potato are tender, so its clean acidity remains noticeable.

Building the Soup Without Letting the Spices Turn Dull

Soften the onion and carrot first

Warm the olive oil in a 6-quart pot over medium heat, then add the diced onion and carrot. Cook for 5 to 7 minutes, stirring occasionally, until both have softened. They should look glossy and lose their raw, firm edges without needing to brown. If the vegetables still feel crisp, give them the full time before adding the garlic and spices.

Let the spices bloom briefly

Add the minced garlic, cumin, coriander, and smoked paprika, then stir for 30 seconds. The garlic should smell fragrant and the spices should coat the softened vegetables. Don’t leave them sitting in the hot oil; ground spices can turn bitter if they scorch. Have the lentils and sweet potato ready to add next.

Simmer until both main ingredients are tender

Stir in the rinsed lentils, sweet potato, vegetable broth, kosher salt, and black pepper. Bring the pot to a boil over high heat, then reduce the heat to maintain a gentle simmer and partially cover it. Cook for 20 to 25 minutes, stirring occasionally, until the lentils have broken down and the sweet potato is very tender. A hard boil can rough up the potato pieces, so keep the bubbles gentle.

Finish with lemon off the main cooking stage

Once the lentils and sweet potato are tender, stir in the fresh lemon juice. Taste a spoonful to notice the balance of earthy spices, sweet potato, and bright citrus. Serve the soup hot. The lemon belongs at the finish rather than during the long simmer, where its fresh edge would fade.

Simple Swaps for a Different Pot of Lentil Soup

Questions That Come Up While This Soup Simmeres

Hearty Red Lentil and Sweet Potato Soup

Red lentil and sweet potato soup simmers into a hearty, thick bowl with tender sweet potato and lentils that break down into the broth. Cumin, smoked paprika, and fresh lemon juice bring warmth and brightness to this one-pot soup.

Print Recipe Pin Recipe

Prep Time 15 minutes mins

Cook Time 33 minutes mins

Total Time 48 minutes mins

Servings: 6 servings

Course: Dinner

Cuisine: American

Calories: 280

Ingredients Method Notes

Ingredients

  

• 1 tbsp olive oil
• 1 yellow onion medium, diced
• 1 carrot medium, diced
• 3 cloves garlic minced
• 1 tsp ground cumin
• 0.5 tsp ground coriander
• 0.5 tsp smoked paprika
• 1.5 cups dried red lentils rinsed and drained
• 1 sweet potato large (about 1 pound), peeled and cut into 1/2-inch cubes
• 6 cups vegetable broth low-sodium
• 1.5 tsp kosher salt
• 0.25 tsp ground black pepper
• 1 tbsp fresh lemon juice

Method

 

1. Heat the olive oil in a 6-quart pot over medium heat.
2. Add the onion and carrot and cook for 5 to 7 minutes, stirring occasionally, until softened.
3. Add the garlic, cumin, coriander, and smoked paprika and cook for 30 seconds, stirring, until fragrant.
4. Stir in the lentils, sweet potato, vegetable broth, salt, and black pepper.
5. Bring the soup to a boil over high heat.
6. Reduce the heat to maintain a gentle simmer and partially cover.
7. Cook for 20 to 25 minutes, stirring occasionally, until the lentils have broken down and the sweet potato is very tender.
8. Stir in the lemon juice and serve hot.

Notes

For the thickest texture, rinse and drain the lentils well before adding them. Refrigerate leftovers for up to 4 days or freeze for up to 3 months. For a lower-sodium bowl, reduce the kosher salt to taste.