Name: Roasted Tomato & Cauliflower Rice Soup
Prep time: 10 min
Cook time: 40 min
Total time: 50 min
Ingredients: 1 tablespoon olive oil; 3 cups cauliflower rice; 2 tomatoes (sliced about 1/4 inch thick); 1 cup chopped kale (stems removed); 1/8 cup fresh basil (coarsely chopped, plus a few leaves for serving); ¼ cup shredded Parmesan cheese (plus more for serving); 4 cups chicken stock (or vegetable stock); salt (to taste); pepper (to taste)

This Roasted Tomato & Cauliflower Rice Soup is a light, brothy bowl packed with oven-roasted tomatoes, tender cauliflower rice, kale, fresh basil and plenty of Parmesan. It's low-carb, gluten-free and comes together with about 10 minutes of hands-on work, so it's an easy soup to keep in your weeknight rotation.

Roasted tomato and cauliflower rice soup in a white bowl topped with shredded Parmesan and a fresh basil leaf

Key Ingredients & Substitutions

Cauliflower rice. Store-bought fresh cauliflower rice is the easiest option, but you can make your own by pulsing cauliflower florets in a food processor until they look like rice. Frozen cauliflower rice works too; thaw it and pat it dry first so it roasts instead of steaming on the pan.
Tomatoes. Two medium slicing or Roma tomatoes are all you need. Roasting concentrates their flavor and gives the broth a gentle sweetness. In a pinch, a pint of halved cherry tomatoes roasts beautifully too.
Kale. Curly or lacinato (Tuscan) kale both hold up well as the soup simmers. Strip out the tough stems before chopping. Baby spinach is a good swap; stir it in during the last 2 minutes so it doesn't turn mushy.
Fresh basil. Basil adds a bright, sweet herb flavor. Save a few small leaves for the top of each bowl. If you only have dried basil, use about 1 teaspoon.
Parmesan cheese. Shredded Parmesan melts into the broth and makes it richer and a little silky. Pecorino Romano or Asiago are good substitutes if you like a sharper, saltier cheese.
Chicken stock. A good-quality stock is the backbone of this soup, so use one you like the taste of. We like Pacific Foods organic unsalted chicken stock because it lets you control the salt. For a vegetarian soup, use vegetable stock instead.
Olive oil, salt and pepper. A little olive oil keeps the vegetables from sticking and helps them brown in the oven. Season at the end once the Parmesan has melted in, since the cheese adds salt of its own.

How to Make Roasted Tomato & Cauliflower Rice Soup Step by Step

Step 1: Preheat the oven to 400°F. Brush a large rimmed baking sheet with the olive oil.

Step 2: Spread the cauliflower rice over the pan in an even layer and arrange the tomato slices on top. Roast for 20 minutes, stirring the cauliflower halfway through, until the tomatoes are soft and the cauliflower is starting to turn golden at the edges.

Cauliflower rice and sliced tomatoes spread on a baking sheet, ready to roast

Step 3: Scrape the roasted cauliflower rice and tomatoes into a large stock pot. Add the chopped kale, fresh basil and shredded Parmesan.

Roasted cauliflower rice, roasted tomatoes, chopped kale, fresh basil and shredded Parmesan in a stock pot

Step 4: Pour in the chicken stock. Bring the soup to a low boil over medium-high heat, then reduce the heat to medium-low and let it simmer for 20 minutes, stirring now and then, until the kale is tender.

Chicken stock added to roasted cauliflower rice, tomatoes, kale, basil and Parmesan in a stock pot

Step 5: Taste and season with salt and pepper. Ladle the soup into bowls, top with a little extra Parmesan and a basil leaf, and serve hot.

Helpful Tips

Give the cauliflower room on the pan. Spread the cauliflower rice as thin as you can. If it's piled up, it steams in its own moisture and never picks up the toasty flavor that makes this soup taste roasted. If your pan is small, use two pans.

Scrape up the browned bits. The tomato juices caramelize on the baking sheet as they roast. Splash a few tablespoons of the stock onto the warm pan and scrape it with a spatula, then pour everything into the pot so none of that flavor goes to waste.

Keep it at a gentle simmer. Once the soup comes to a boil, turn it down. A hard, rolling boil can make the Parmesan clump and stick to the bottom of the pot instead of melting smoothly into the broth.

Salt at the end. Stock and Parmesan both bring salt, and the amount varies a lot by brand. Wait until the soup has simmered, then taste it and add salt a pinch at a time.

Save some basil for serving. Basil that simmers for 20 minutes adds flavor to the broth but loses its bright color. A few fresh leaves on top of each bowl bring back that fresh basil aroma right before you eat.

Variations

Make it vegetarian. Swap the chicken stock for vegetable stock and use a Parmesan made without animal rennet.
Add protein. Stir in 2 cups of shredded rotisserie chicken or a can of drained white beans during the last 5 minutes to turn this into a heartier meal.
Make it creamy. Stir in ¼ cup of heavy cream just before serving, or blend half of the soup with an immersion blender for a thicker texture.
Pesto swirl. Top each bowl with a spoonful of homemade basil pesto for an extra hit of basil and garlic.
Add some heat. A pinch of red pepper flakes in the pot, or a drizzle of chili oil on top, gives the soup a gentle kick.
Roast more vegetables. Add a sliced onion, a few garlic cloves or chopped zucchini to the baking sheet along with the tomatoes.

Serving Ideas

This soup is light enough to serve as a starter and satisfying enough to be lunch on its own. For a cozy soup-and-bread dinner, pair it with a warm loaf of Copycat Macaroni Grill Rosemary Bread or a gooey heirloom tomato grilled cheese for dipping.

To keep things low-carb, crumble a few easy keto cheese crisps over the top in place of croutons. If you want a more filling meal, serve a small bowl as a side alongside crispy Southern Fried Pork Chops or a simple green salad.

Storing & Freezing

Let the soup cool, then store it in an airtight container in the refrigerator for up to 4 days. The flavors keep getting better as it sits. Reheat individual portions in the microwave or the whole batch on the stove over medium heat, adding a splash of stock if the broth has reduced.

To freeze, pack the cooled soup into freezer-safe containers, leaving about an inch of headspace, and freeze for up to 3 months. The kale and cauliflower soften a little after freezing, but the flavor holds up well. Thaw overnight in the refrigerator, then reheat on the stove until steaming and top with fresh Parmesan and basil.

Bowl of roasted tomato and cauliflower rice soup with Parmesan and basil beside a teal patterned napkin

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