Soups

September 10, 2021

Easy Oven Roasted Vegan Tomato Basil Soup

This Vegan Tomato Basil Soup is easy to make and so creamy. It's made with roasted tomatoes, cauliflower, and onions, then thickened with cashews and basil pesto. It's the perfect soup for fall!

Growing up, whenever I was sick, I always wanted the fresh and warm tomato soup from the grocery store. It was creamy, well-seasoned, and perfect with fresh bread. It just warmed the soul, you know?

Well last year, I really wanted to write my own tomato soup recipe that used lots of fresh veggies and wholesome ingredients. I developed, tested, and photographed the recipe, but hated the final images.

So I reluctantly decided to wait an entire year to try again until I was more confident in my photography.

Well I am SO glad I did because I am in love with these images and the recipe is even better this time around! I accidentally made it vegan too, haha.

Today's Vegan Tomato Basil Soup is packed with fresh roasted vegetables, heart- healthy fats, plant-based protein, and a secret ingredient that really makes this homemade tomato basil soup the best!

Bowls of roasted tomato basil soup with a pesto swirl on top

Ingredients for vegan tomato basil soup

  • Roma tomatoes: I prefer these tomatoes over other types of tomatoes because they are less watery, but really, you can use any tomatoes you like. Just make sure you get 3 pounds!
  • Cauliflower florets: to help thicken the soup and make it creamy. Fresh or frozen will work, but if you're using frozen florets, make sure to thaw them prior to roasting. We don't want the veggies to boil, we want them to roast!
  • Aromatics: onions and garlic for good measure. Don't skimp on either!
  • Cashews: the other secret to a thick and creamy soup without using any dairy. Be sure to soak them before blending!
  • Nutritional yeast: a nutty, vegan-friendly substitute for parmesan cheese that adds a boost of plant-based protein and all the B vitamins. If you've never had it, please try it. It's one of my pantry staples that I use for a lot of my recipes!
  • Homemade basil pesto: the "secret ingredient" that really sets this homemade tomato basil soup apart from all the others. Grab the recipe here and make sure to save some leftovers because it's so good!
  • Fresh basil: optional but highly recommended. Since you're making homemade pesto anyway, you might as well use the extra basil leaves!

A pot of roasted tomato basil soup

How to make roasted tomato basil soup

Add the cashews to a bowl of very hot water and let them soak while you prepare the soup.

Preheat the oven to 400°F and spray a 9x13 casserole dish with cooking spray.

Toss all the tomatoes, cauliflower, onion, and garlic cloves in the olive oil and generously season with salt and pepper.

Add to the casserole dish and roast for 40 minutes. The vegetables should slightly charred and very fragrant when they're done.

Use a slotted spoon to remove the vegetables from the baking dish and add to a large blender. We don't want any excess liquid in the soup! Drain the cashews and add to the blender with the remaining ingredients. Blend until smooth.

A pan of roasted tomatoes and veggies for tomato basil soup

From here, you can either serve immediately OR you can add the soup to a large pot and reduce it on low heat on the stove for 15-20 minutes. Reducing it will make it even thicker!

Not sure what to serve with your homemade tomato basil soup? Try these Everything But the Bagel Dinner Rolls or my Chicken Caprese Grilled Cheese Melts!

Frequently Asked Questions

Is tomato soup good for you?

Yes! Homemade tomato soup uses a variety of vegetables and minimal ingredients. It's traditionally lower calorie, unless whole milk or heavy cream is used.

What makes this a vegan tomato basil soup?

Instead of thickening the soup with dairy products like whole milk or heavy cream, I chose to use more nourishing ingredients like cauliflower and cashews. If you like your soup a little thinner, you can always add almond or cashew milk! I also used nutritional yeast in place of regular parmesan cheese.

A blender of roasted vegetables

Does this homemade tomato basil soup use canned tomatoes?

Nope! All the vegetables in this tomato soup recipe are fresh.

What goes with tomato basil soup?

Traditionally, tomato soup is served with grilled cheese sandwiches, but I also love garlic bread, homemade dinner rolls (click here for my recipe!), and including a side of protein like grilled chicken.

Is tomato soup American?

The earliest known tomato soup recipe dates back to the mid 1800s in the United States. Prior to this time, most soups had a variety of vegetables instead of one main vegetable.

What's the difference between tomato soup and tomato bisque?

Tomato soup is mostly vegetable based and thickened with vegetable broth, where tomato bisque is thickened with milk or heavy cream. This easy tomato basil soup recipe does not use any dairy; it's thickened with cauliflower, cashews, and the juices from the tomatoes!

A bowl of roasted tomato basil soup

More easy and cozy recipes

60 Minute Instant Pot Beef Stew

Easy Healthy Baked Potato Soup

One Pot Chili con Carne

90 Minute Everything But The Bagel Dinner Rolls

Easy Oven Baked Mac and Cheese

Protein Packed Spinach Lasagna Rolls

Guilt-Free Vegan Sweet Potato Casserole

A bowl of Vegan Tomato Basil Soup with pesto and fresh basil on top

Please please please make this as soon as possible! This roasted tomato basil soup is such a great way to get your veggies in and an even better excuse to enjoy a hearty, cheese grilled cheese like this one.

Be sure to leave a star rating and review below if you try the recipe so other readers know how you liked it!

Easy Oven Roasted Vegan Tomato Basil Soup

This Vegan Tomato Basil Soup is easy to make and so creamy. It's made with roasted tomatoes, cauliflower, and onions, then thickened with cashews and basil pesto. It's the perfect soup for fall!

Author:

Brooke Harmer

Prep:

20

min

cook:

40

min

total:

60

min

servings:

8

Ingredients

  • 3 lbs. Roma tomatoes, quartered
  • 8 oz. cauliflower florets
  • 1 onion, roughly chopped
  • 8  cloves garlic, peeled
  • 3 Tbsp olive oil
  • ¼ C unsalted cashews
  • 6 Tbsp nutritional yeast
  • ¼ C homemade Basil Pesto
  • ½ C  fresh basil (optional)
  • 1 tsp salt
  • 1 tsp red chili flakes

Instructions

  1. Add the cashews to a bowl of very hot water and let soak while you prepare the soup. Set aside.
  2. Preheat the oven to 400°F and spray a 9x13 casserole dish with cooking spray.
  3. Toss all the tomatoes, cauliflower, onion, and garlic cloves in the olive oil and generously season with salt and pepper. Add to the casserole dish and bake for 40 minutes. The vegetables should slightly charred and very fragrant when they're done.
  4. Use a slotted spoon to remove the vegetables from the baking dish and add to a large blender. Drain the cashews and add to the blender with the remaining ingredients. Blend until smooth.* Serve immediately with your favorite side dish!
  5. Optional: pour the soup into a large pot and reduce over low heat for an additional 15-20 minutes if you like a thicker soup.

Notes

*If you like a thinner soup, add your favorite non-dairy milk 2 tablespoons at a time until the soup is just how you like it.

Nutrition facts are a calculated estimate of 1 cup of Tomato Basil Soup.

Nutrition

Serving: 1 cup / Calories: 140 / Fat: 7.9g / Saturated Fat: 1.3g / Carbohydrates: 13.7g / Fiber: 3.9g / Sugar: 5.6g / Protein: 6.6g