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overhead view of a bowl of roasted sweet potato and cauliflower soup with toppings


Why make this Roasted Sweet Potato and Cauliflower Soup?

The reasons to make this soup recipe are because it is incredibly easy and quick to make, I included specific ingredients so that it contains 23g of protein per serving, which is more than many veggie-based meals, and the soup tastes great based on adding in fresh herbs and key spices.


  • Roasted Veggies: sweet potato and cauliflower for the base of the soup.
  • Lentils: pre-cooked or canned lentils are used so there is no preparation required.
  • Greek Yogurt: spices and fresh herbs are added to the yogurt to create a high protein and flavorful topping for the soup.
  • Fresh herbs: dill and chives add a punch of flavor to the yogurt topping and create a showstopper soup if you are serving to guests.
  • Ground Spices: smoked paprika, garam masala, and turmeric create a blend of flavors that brings the soup and spiced yogurt to life
  • Veggie Broth: this adds flavor and allows you to thin the pureed roasted veggies enough to create the ideal soup texture.


  • Roast the veggies: cubed sweet potato and cauliflower florets are roasted with olive, then some are kept aside while the rest are pureed with veggie broth and spices
  • Mix ingredients in soup pot: the veggies are added to a soup pot with the pre-cooked lentils and the roasted veggies that were not pureed. The soup is slowly heated and the spices are adjusted.
  • Make the spiced yogurt: while the veggies roast, or when the soup is heating, mix the fresh chopped herbs and spices with the yogurt to make the topping.
  • That’s it! Once in serving bowls, the soup is topped with yogurt and fresh herbs, as well as a squeeze of lemon if you like the brightness it adds.


  • Veggies: you could substitute any kind of sweet potato (white or Japanese purple) but you will get a different colored soup. Any orange winter squash will work but will be harder to prepare, as you’ll need to remove the thick skin from the winter squash.
  • Lentils: you can use any lentil you prefer or have on hand. The small beluga lentils are delicate in flavor and don’t overwhelm. Red lentils would work well, but you aren’t likely to find them canned or have them pre-cooked as they get mushy fast. Other precooked lentils will work fine.
  • Herbs: you could substitute other fresh herbs and they will all work, as long as you like their flavors. Suggestions are cilantro, parsley, thyme, and tarragon (if you like an anise/licorice-type flavor). Green onions could be used in place of the chives.


I find these kinds of blended soups are thinner the night I make them and thicken up the next day, just FYI. However, I enjoy this soup after night one just as much, and you could thin the soup on night two with more veggie broth if desired.

a collage of photos showing herbs, spiced yogurt and soup being served with dog looking on.
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overhead view of a bowl of roasted sweet potato and cauliflower soup with toppings

Roasted Sweet Potato and Cauliflower Soup

AuthorKathy Marshall
5 from 1 vote
Prep Time20 minutes
Cook Time45 minutes
Roasted vegetables form the base of this thick soup, made flavorful with warm spices. The addition of cooked beluga lentils and a topping of spiced yogurt make this soup high protein.
Kitchen Tools
  • 1 3 quart soup pot
  • 1 baking sheet
  • 1 blender, or food processor


  • 4 cups cubed sweet potato (2-3 medium)
  • 1 ea medium head cauliflower
  • 1 cup cooked black lentils (a.k.a.beluga, caviar lentils)
  • 1 cup vegetable boullion (I use low-sodium)
  • 1 tsp smoked paprika
  • 1 tsp garam masala
  • 1 tsp turmeric
  • 1/4 tsp cayenne
Spiced Yogurt Topping
  • 1 cup greek yogurt (or regular, or plant-based)
  • 1 handful fresh dill
  • 1 handful fresh chives
  • 1 pinch smoked paprika
  • 1 pinch garam masala
  • 1 pinch turmeric
  • 1 pinch cayenne
  • 1 wedge lemon


  • IF YOU DON'T HAVE COOKED OR CANNED LENTILS ON HAND YOU CAN STILL MAKE THIS SOUP BUT IT WILL TAKE AN EXTRA 15 MINUTES: Cook the lentils first, separately from the soup. Rinse dry lentils, then cover with 1-2" water and boil/simmer for about 15 minutes until they taste done- not too crunchy, not too mushy, and drain.
  • Cube the sweet potatoes (smallish) and break the cauliflower into small florets. Lay on a baking tray, using your liner of choice, and drizzle with a tablespoon or so of olive oil (don't overdo it here, they don't need much). Roast in top 1/3 of oven at 425 for about 15 minutes. At that point, I usually lose my patience and turn the oven to broil for a few minutes to give the veggies a little char and caramelization.
  • Into a high-speed blender or food processor (this soup is thick enough that it shouldn't leak out of a food processor), place about 2/3-3/4 of the roasted veggies. Reserve the rest to stir into the blended soup still intact. Add 1 cup of veggie broth or water, and the 4 spices, and blend until smooth.
  • Place blended soup into a saucepan (I use a 3 quart), and begin to heat on low to medium-low. Add in the cooked lentils and the remaining roasted veggies and heat slowly, making sure to stir, so the soup does not stick. (soups with legumes added in have a tendency to stick at some point).
  • Taste the soup. Salt the soup as you like (I don't use much salt). Add more spices if you want more heat or more flavor (but take care w/the garam masala as it can be a bit bitter if used too liberally).
  • Meanwhile, finely chop the fresh herbs and stir into the cup of yogurt. Add some of each of the 4 spices. I'd go heavier on the turmeric and lighter on the garam masala. Maybe 1/2 tsp of each to start. It really depends on your taste buds. Squeeze some lemon into the spiced yogurt, to taste.
  • Top each serving of soup with about 1/4 c of the yogurt, a sprinkle of the herbs, and if you like, a tiny drizzle of olive oil and a squeeze of lemon for extra flavor.
  • Crusty toasted bread topped with spiced yogurt and drizzles of olive oil and honey (try hot honey!) is an excellent accompaniment to the soup.


Note: I find these kinds of blended soups are thinner the night I make them and thicken up the next day, just FYI. I enjoy this soup after night one just as much.

Nutrition (an estimate)

Calories: 346kcal | Carbohydrates: 63g | Protein: 23g | Fat: 1g | Saturated Fat: 0.3g | Cholesterol: 3mg | Sodium: 139mg | Potassium: 993mg | Fiber: 18g | Sugar: 10g | Vitamin C: 78mg | Calcium: 163mg | Iron: 6mg
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Recipe Rating


  1. 5 stars
    This recipe was easy and delicious! We have also made the spiced yogurt as a topping for other meals. Will definitely make this again!!