Vegan Roasted Butternut Squash and Leek Soup

There’s something about fall that makes me want soup for every meal. Maybe it’s the cooler weather, or maybe I just love having an excuse to turn on the oven. Either way, I’m always looking for new soup recipes to add to my rotation.

This roasted butternut squash and leek soup has become one of my go-to recipes when I need something warm and filling. The roasting part is key here. It brings out the natural sweetness in the squash and gives the soup more flavor than just boiling everything in a pot. Plus, you can throw the vegetables in the oven and walk away for a bit.

I like making a big batch on Sunday and eating it throughout the week. It reheats well, and honestly, it tastes even better the next day. Serve it with some crusty bread, and you’ve got yourself a complete meal that doesn’t require much effort.

What Kind of Butternut Squash Should I Use?

Any butternut squash you find at the grocery store or farmers market will work great for this soup. Look for one that feels heavy for its size and has a hard, matte skin without any soft spots or bruises. The longer neck portion of the squash has more solid flesh and fewer seeds, so if you’re choosing between a few, go for one with a longer neck. If you’re short on time, many stores now sell pre-cut butternut squash in the produce section, which can save you about 15 minutes of prep work – just make sure the pieces look fresh and aren’t dried out around the edges.

Options for Substitutions

This soup is pretty forgiving when it comes to swapping ingredients:

• Butternut squash: You can use other winter squash like acorn, kabocha, or even sweet potatoes. They’ll give you a similar creamy texture, though the flavor will be slightly different. Cooking times should stay about the same.
• Leeks: If leeks aren’t available, use 2 medium yellow onions instead. They’ll give you that sweet, mild onion flavor that works great in this soup.
• Granny Smith apple: Any tart apple works here – try Honeycrisp or Fuji if that’s what you have. The apple adds a nice hint of sweetness and helps balance the soup.
• Fresh sage: Don’t have fresh sage? Use 1 teaspoon of dried sage instead. Add it when you add the nutmeg so it has time to bloom in the oil.
• Vegetable broth: Chicken broth works perfectly fine if you’re not keeping this vegetarian. You can also use water in a pinch, though you might want to add a bit more salt to make up for the lost flavor.

Watch Out for These Mistakes While Cooking

The biggest mistake when roasting butternut squash is cutting it into uneven pieces, which leads to some chunks being burnt while others remain undercooked – aim for uniform 1-inch cubes so everything caramelizes at the same rate.

Leeks are notorious for trapping dirt and sand between their layers, so make sure to slice them first, then soak in cold water and rinse thoroughly before cooking, or you’ll end up with a gritty soup.

Don’t rush the roasting process by cranking up the oven temperature – butternut squash needs time at around 400°F to develop its natural sweetness, and pulling it out too early means you’ll miss out on those caramelized edges that give the soup its depth.

When blending hot soup, always start on low speed and never fill your blender more than halfway full, or the steam pressure can cause the lid to pop off and create a dangerous mess.

What to Serve With Butternut Squash Soup?

This soup is pretty filling on its own, but I love serving it with a crusty baguette or some toasted sourdough for dipping. A simple arugula salad with apple slices and walnuts makes a great side since it echoes the apple already in the soup and adds a nice peppery contrast to the sweetness. If you want to make it more of a complete meal, try adding a grilled cheese sandwich on the side, or top the soup with some crispy bacon bits and toasted pumpkin seeds for extra crunch. For a fancier touch, a drizzle of brown butter and some fresh sage leaves on top really brings out the fall flavors.

Storage Instructions

Store: This soup keeps really well in the fridge for up to 5 days in an airtight container. The flavors actually get better after a day or two, so it’s great for making ahead. I love having it ready to go for easy lunches throughout the week.

Freeze: Butternut squash soup is one of the best soups for freezing. Let it cool completely, then store it in freezer-safe containers or bags for up to 3 months. I like to freeze it in smaller portions so I can thaw just what I need.

Reheat: Warm the soup gently on the stovetop over medium-low heat, stirring occasionally. You can also microwave individual portions, but I prefer the stovetop since it heats more evenly. If the soup seems too thick after storing, just add a splash of broth or water to thin it out.

Estimated Nutrition

Estimated nutrition for the whole recipe (without optional ingredients):

• Calories: 450-550
• Protein: 6-8 g
• Fat: 22-28 g
• Carbohydrates: 65-75 g

Ingredients

For roasting the squash:

• 1 large butternut squash (about 2 1/2 lb)
• 1/2 tbsp olive oil
• Salt, to taste

For the soup base:

• 3 leeks, white and pale green parts, sliced in rings
• 1 granny smith apple, diced
• 4 minced garlic cloves
• 1 tbsp chopped fresh sage
• 1/8 tsp ground nutmeg
• 1 quart vegetable broth
• 1 1/2 tbsp olive oil
• 1/4 tsp salt

Step 1: Prep and Roast the Butternut Squash

• 1 large butternut squash (about 2 1/2 lb)
• 1/2 tbsp olive oil
• salt, to taste

Preheat your oven to 400°F.

Trim the stem and hard bottom end off the butternut squash, then cut it in half lengthwise.

Use a spoon to scoop out and discard the seeds.

Drizzle the squash flesh with olive oil and sprinkle with a pinch of salt, spreading the oil evenly with your hands.

Place the squash halves skin side up on a baking sheet and poke several holes in each half.

Roast for 40–45 minutes, or until the flesh is fork-tender and the skin looks wrinkly.

Flip the squash halves over and let them cool until you can handle them safely.

Step 2: Sauté Aromatics and Apple

• 1 1/2 tbsp olive oil
• 3 leeks, white and pale green parts, sliced in rings
• 1 Granny Smith apple, diced
• 4 minced garlic cloves
• 1 tbsp chopped fresh sage
• 1/8 tsp ground nutmeg
• 1/4 tsp salt

While the squash is roasting, heat 1 1/2 tablespoons of olive oil over medium heat in a large pot on the stovetop.

Add the sliced leeks, diced Granny Smith apple, minced garlic, chopped fresh sage, ground nutmeg, and 1/4 teaspoon of salt to the pot.

Cook, stirring occasionally, for 3–5 minutes, until the leeks are soft and fragrant and the apples just begin to soften.

I like to take this time to inhale the beautiful aroma from the leeks, apple, and sage mingling together.

Step 3: Simmer the Soup Base

• 1 quart vegetable broth

Add the vegetable broth to the pot with the sautéed ingredients.

Bring the mixture to a boil, then reduce the heat to a simmer and cover the pot.

Let it continue to simmer while the butternut squash finishes roasting in the oven.

This helps all the flavors meld together nicely.

Step 4: Add Roasted Squash and Finish Cooking

• roasted butternut squash (from Step 1)

Once the butternut squash is cool enough to handle, scoop the roasted flesh out of the skin and add it directly to the pot with the simmering soup base.

Stir thoroughly to combine all the ingredients.

Continue to simmer for a few more minutes to allow the roasted squash flavor to fully infuse the soup.

For an extra depth of flavor, I sometimes add just a splash more olive oil at this stage, but that’s optional.

Step 5: Blend the Soup Until Creamy

• soup mixture with roasted squash (from Step 4)

Use a ladle to carefully transfer the hot soup into a stand-up blender.

Blend on high for about 1 minute, or until the soup is very smooth and creamy with no lumps.

If needed, work in batches to avoid overfilling your blender.

Return the blended soup to the pot, taste, and adjust seasoning if desired.

Step 6: Serve the Soup

Pour the creamy butternut squash soup into bowls.

Garnish with freshly cracked black pepper and a pinch of flaky sea salt if desired.

Serve hot and enjoy—the soup pairs wonderfully with crusty bread.

Vegan Roasted Butternut Squash and Leek Soup

Delicious Vegan Roasted Butternut Squash and Leek Soup recipe with step-by-step instructions.

Print Recipe Pin Recipe

Prep Time 20 minutes mins

Cook Time 42 minutes mins

Total Time 1 hour hr 2 minutes mins

Servings: 4

Calories: 500

Ingredients Method

Ingredients

  

For roasting the squash:

• 1 large butternut squash (about 2 1/2 lb)
• 1/2 tbsp olive oil
• salt, to taste

For the soup base:

• 3 leeks, white and pale green parts, sliced in rings
• 1 Granny Smith apple, diced
• 4 minced garlic cloves
• 1 tbsp chopped fresh sage
• 1/8 tsp ground nutmeg
• 1 quart vegetable broth
• 1 1/2 tbsp olive oil
• 1/4 tsp salt

Method

 

1. Preheat your oven to 400°F. Trim the stem and hard bottom end off the butternut squash, then cut it in half lengthwise. Use a spoon to scoop out and discard the seeds. Drizzle the squash flesh with olive oil and sprinkle with a pinch of salt, spreading the oil evenly with your hands. Place the squash halves skin side up on a baking sheet and poke several holes in each half. Roast for 40–45 minutes, or until the flesh is fork-tender and the skin looks wrinkly. Flip the squash halves over and let them cool until you can handle them safely.
2. While the squash is roasting, heat 1 1/2 tablespoons of olive oil over medium heat in a large pot on the stovetop. Add the sliced leeks, diced Granny Smith apple, minced garlic, chopped fresh sage, ground nutmeg, and 1/4 teaspoon of salt to the pot. Cook, stirring occasionally, for 3–5 minutes, until the leeks are soft and fragrant and the apples just begin to soften. I like to take this time to inhale the beautiful aroma from the leeks, apple, and sage mingling together.
3. Add the vegetable broth to the pot with the sautéed ingredients. Bring the mixture to a boil, then reduce the heat to a simmer and cover the pot. Let it continue to simmer while the butternut squash finishes roasting in the oven. This helps all the flavors meld together nicely.
4. Once the butternut squash is cool enough to handle, scoop the roasted flesh out of the skin and add it directly to the pot with the simmering soup base. Stir thoroughly to combine all the ingredients. Continue to simmer for a few more minutes to allow the roasted squash flavor to fully infuse the soup. For an extra depth of flavor, I sometimes add just a splash more olive oil at this stage, but that's optional.
5. Use a ladle to carefully transfer the hot soup into a stand-up blender. Blend on high for about 1 minute, or until the soup is very smooth and creamy with no lumps. If needed, work in batches to avoid overfilling your blender. Return the blended soup to the pot, taste, and adjust seasoning if desired.
6. Pour the creamy butternut squash soup into bowls. Garnish with freshly cracked black pepper and a pinch of flaky sea salt if desired. Serve hot and enjoy—the soup pairs wonderfully with crusty bread.