Roasted Sweet Potato & Red Lentil Soup with Harissa

This cozy and comforting Roasted Sweet Potato and Red Lentil Soup is the perfect pick-me-up for lunch or dinner in Fall and Winter. Warmly spiced with harissa which offsets the sweet roasted vegtables. Make a batch and serve with plenty of Vegan Garlic Bread cooked in the Air Fryer for the ultimate comfort bowl.

this recipe

🍠Key Ingredients

Here are the ingredients you'll need to make this sweet potato soup. Please jump to the recipe card for quantities and timings.

1. Sweet Potatoes: Full of fiber and beta-carotenes. Sweet and even better when baked in spicy harissa. Choose firm sweet potatoes and peel.
2. Red Lentils: these add both fibre and protein to help keep you full longer.
3. Ripe Tomatoes: Large ripe tomatoes are delicoius when roasted in this soup.
4. Red Peppers: Roast the peppers whole but remove any seeds and the top from the pepper.
5. Harissa Paste: This spicy North African paste has an addictive heat, made with chilis, garlic and spices such as cumin and coriander seed. Buy it in supermarkets or specialty stores. Why not try my Carrot Tempeh Harissa Fritters to help use up a jar.
6. Onions, Garlic and Seasonings: Whole roasted garlic and chunks of onions or shallots help round out the flavor! Of course sea salt and a good glug of olive oil.

See recipe card for quantities.

Here are some easy swaps you can make with this sweet potato lentil soup recipe:

• Canned (Tinned) Tomatoes: - swap out the tomatoes with a tin of whole tomatoes, juice and all. Add to the baking tray and bake up to caramelise their juices.
• Other Spices: - Can't find harissa paste? Use chipotle paste, or your favourite garam masala (curry powder), a little fresh ginger and some cinnamon and paprika are also good additions.
• Other Vegetables: - Choose carrots to replace the sweet potatoes, and you can use red bell pepper to replace the romano pepper. Stir in some spinach or finely chopped kale into the soup while you're reheating it at the end to add in some greens.

👩‍🍳Instructions

Follow along to make the best roasted sweet potato and lentil soup! Head to the recipe card for quantities and timings.

1. Step 1: Peel the sweet potatoes, chop the top off the garlic. Add the chopped peppers and whole tomatoes to a large baking tray. Sprinkle over olive oil, seasonings and harissa and mix.

2. Step 2: Put the baking tray with the vegetables and roast until tender and slightly caramelised.

3. Step 3: While the vegetables are roasting, add red lentils to a pot with bouillon powder and water (or vegetable broth or stock) and simmer until soft.

4. Step 4: Squeeze out the whole garlic into the vegetables and put aside the husk. Add all the roasted sweet potatos and other veggies, including their juices, plus the cooked red lentils with their cooking water to a blender.

5. Step 5: Blend until smooth. You can leave the soup a little chunky if you prefer that texture. Reheat the soup and taste for seasoning. Add a squeeze of lemon juice or a little white wine vinegar and salt to taste.

6. Step 6: Serve with tahni drizzle or a little vegan yoghurt and some herbs sprinkled over the top.

Hint: If you make this soup too spicy, why not try adding a can of coconut milk to the soup and then reheat it.

Make this Lentil Sweet Potato Soup a Meal!

This delicious lentil and sweet potato soup is really hearty on it's own, but it would also be delicious as a starter for Thanksgiving or a Friendsgiving - or just a Fall get-together. Add some crunchy Tofu Bacon Bits or Savoury Chickpea Granola for guests to sprinkle over the top, and be sure to serve up with some homemade Chickpea Flour Enriched Flatbreads to mop up the soup bowl!

❓Sweet Potato Lentil Soup FAQ

📖 Recipe

Roasted Sweet Potato & Red Lentil Soup with Harissa

Louise-Claire Cayzer

A cozy fall soup packed with spices and flavor from the Harissa and sweetness from roasted vegetables.

5 from 1 vote

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Prep Time 10 minutes mins

Cook Time 35 minutes mins

Soup reheating time 5 minutes mins

Total Time 53 minutes mins

Course Soup

Cuisine Vegan

Servings 6 portions

Calories 246 kcal

Equipment

• 1 large baking pan
• 1 Blender (or immersion blender)

Ingredients Note:

For accuracy, I measure all ingredients in metric as standard, then convert and test the recipe for American cup measurements etc.

(Heads up Aussie and UK readers- your measurements in cups are sometimes different, so please use metric or check you have the correct cup and spoon type!!)

Ingredients

Roasted Veggies

• ▢ 360 g (2 5/7 cups) sweet potatoes (two small sweet potatoes roughly chopped)
• ▢ 200 g (1 ⅓ cups) bell peppers
• ▢ 400 g (⅞ lb) whole tomatoes
• ▢ 100 g (¼ cup) shallot (or small onion)
• ▢ 1 bulb garlic
• ▢ 1 tablespoon harissa paste (more if you like it spicy)
• ▢ 1 tablespoon olive oil
• ▢ sea salt to taste
• ▢ 1 teaspoon lemon juice (or white wine vinegar)

Lentils

• ▢ 180 g (1 cup) red lentils
• ▢ 500 ml (2 cups) water
• ▢ 2 teaspoon boullion powder

Tahini Drizzle (optional

• ▢ 2 tablespoon tahini
• ▢ 30 ml (⅛ cup) lemon juice
• ▢ 60 ml (¼ cup) warm water
• ▢ sea salt to taste
• ▢ ¼ teaspoon (¼ teaspoon) harissa mixed with a little olive oil (for colour)

Instructions

• Peel and chop the sweet potatoes and onion/shallot.
• De-seed and roughly chop the bell peppers.
• Cut the top off the garlic bulb.
• To a large baking pan, add the sweet potatoes, peppers, onions, tomatoes and the garlic bulb cut side up.
  360 g sweet potatoes, 200 g bell peppers, 400 g whole tomatoes, 100 g shallot, 1 bulb garlic
• Drizzle everything in the pan with a little olive oil, sprinkle over the harissa and a little salt and mix it in.
  1 tbsp harissa paste, 1 tbsp olive oil, sea salt to taste
• Add a little extra oil to the garlic bulb.
• Roast at 180℃ or 360℉ for 35 minutes or until the sweet potato is soft and a little caramelised and the garlic is soft when you (carefully) squeeze it). - Mix half way to ensure even cooking.
• Allow to cool a little.
• While the vegetables are roasting, add the dry lentils to a sauce pan with the water (OR vegetable stock) and the boullion powder.
  180 g red lentils, 500 ml water, 2 tsp boullion powder
• Simmer over a medium heat until soft. Stir occassionally and don't let the lentils run dry!
• Add the lentils and all the cooked roasted vegetables, including the roast vegetable juices to a blender. Blend until creamy.
Don't waste the juices from the baking tin- they should all get used in the soup when blending!
• Put the soup into a large pot to reaheat. If it's too thick, add a little water (vegetables can vary quite dramatically on how much liquid they give out, so go by how you like your soup.
  1 tsp lemon juice
• Taste and add a little lemon juice or white wine vinegar bit by bit to balance the sweetness and add any salt or extra harissa to taste.

Optional Tahini Dressing

• In a small blender or jar, blend or mix up the tahini, lemon juice and water . Add water bit by bit until you get a pourable consistency.
  2 tbsp tahini, 30 ml lemon juice, 60 ml warm water, sea salt to taste
• Mix a small amount of harissa with olive oil, then drop over the soup, along with the tahini dressing for a pretty swirled effect that also tastes delicious.
  ¼ tsp harissa mixed with a little olive oil

Notes

• Don't waste the juices from the baking tin- they should all get used in the soup when blending!
• If you don't want to blend the soup in a blender, cook the lentils in a larger pot, and tip the roasted veggies into that pot and use an immersion blender. 
• Serves 6 small portions for an elegant starter for dinner or 4 larger portions suitable for lunch! 
• You can roast the vegetables in the air fryer- keep the same temperature, but the time should be around 30 mins to roast, depending on your air fryer basket it might be less. 

Nutrition

Calories: 246kcalCarbohydrates: 40gProtein: 11gFat: 6gSaturated Fat: 1gPolyunsaturated Fat: 2gMonounsaturated Fat: 3gCholesterol: 0.1mgSodium: 255mgPotassium: 815mgFiber: 13gSugar: 8gVitamin A: 10144IUVitamin C: 59mgCalcium: 61mgIron: 3mg

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