Flavorful Tomato Zucchini Lasagna Soup

If you ask me, zucchini lasagna soup is one of those cozy meals that just makes sense.

This warming Italian-inspired soup brings together all the flavors of traditional lasagna but in a lighter, broth-based version. Fresh zucchini and tender noodles swim in a rich tomato broth that’s dotted with herbs and spices.

It’s loaded with Italian sausage and creamy ricotta cheese, plus a generous helping of melted mozzarella that creates those stretchy cheese pulls we all love from regular lasagna. A sprinkle of fresh basil brings the whole dish together.

It’s a comforting bowl that feels like a hug from an Italian grandmother, perfect for those nights when you want lasagna flavor without all the layering work.

What Kind of Zucchini Should I Use?

When shopping for zucchini to spiralize, look for ones that are medium-sized – about 6 to 8 inches long and 1.5 to 2 inches wide. These work best because they’re easier to handle and create longer, more consistent noodles than smaller or larger ones. Fresh, firm zucchini is key here – avoid any that feel soft or have wrinkled skin, as they won’t spiralize well. If you can find straight rather than curved zucchini, they’ll be easier to work with and give you better results. Just make sure to trim off both ends before spiralizing, and if your zucchini is particularly watery, you can sprinkle the noodles with a bit of salt and let them sit in a colander for 10 minutes to remove excess moisture.

Options for Substitutions

This soup is pretty flexible and you can make several swaps based on what you have in your kitchen:

• Zucchini noodles: If you don’t have a spiralizer, you can use a regular vegetable peeler to create ribbons, or simply cut the zucchini into small chunks. You could also swap in yellow summer squash, or use regular lasagna noodles broken into pieces (cook separately first).
• Brown lentils: Green lentils work perfectly here too. Red lentils can be used but they’ll cook faster and create a thicker soup. You could also use white beans or chickpeas instead – just reduce cooking time since they’re already cooked.
• Crushed tomatoes: Diced tomatoes work fine – you’ll just have a chunkier texture. In a pinch, you can use tomato sauce plus 1 tablespoon of tomato paste.
• Vegetable broth: Feel free to use chicken broth if you’re not keeping it vegetarian. You can also use bouillon cubes with water (follow package instructions for ratio).
• Mozzarella cheese: Any Italian-style cheese works great here – try provolone, parmesan, or dairy-free alternatives if you’re keeping it vegan. You can even skip the cheese altogether.
• Fresh basil: If fresh basil isn’t available, use 1 tablespoon dried basil, or try fresh parsley instead.

Watch Out for These Mistakes While Cooking

The biggest challenge when making zucchini lasagna soup is preventing your zucchini noodles from becoming mushy – add them during the last 3-4 minutes of cooking to keep them perfectly al dente. A common error is overcooking the lentils, which can turn them into mush; instead, simmer them until they’re just tender but still hold their shape, usually around 20-25 minutes. Another mistake to avoid is adding the fresh basil too early in the cooking process, which will make it lose its bright flavor – stir it in right before serving, along with the cheese, to preserve its fresh taste. For the best texture and flavor development, make sure to sauté the onions, carrots, and celery until they’re properly softened before adding the other ingredients, as rushing this step can result in uneven cooking and less developed flavors.

What to Serve With Zucchini Lasagna Soup?

This cozy soup is already packed with veggies and protein from the lentils, so it pairs perfectly with some crusty garlic bread or a warm Italian bread roll on the side. If you’re looking to round out the meal, try serving it with a simple Caesar salad or mixed green salad dressed with light Italian vinaigrette. For an extra special touch, I like to put out a small bowl of extra shredded mozzarella and fresh basil leaves so everyone can add their own toppings – it makes the whole experience feel like you’re eating actual lasagna in soup form!

Storage Instructions

Keep Fresh: This tasty soup will stay good in the fridge for up to 5 days when kept in an airtight container. The zucchini noodles might get a bit softer over time, but the flavors actually get better as they meld together! It’s perfect for making on Sunday and enjoying throughout the week.

Freeze: If you want to freeze this soup, I recommend doing it without the zucchini noodles and cheese. Pour the cooled soup into freezer-safe containers, leaving some space for expansion, and it’ll keep for up to 3 months. When you’re ready to eat, just add fresh zucchini noodles while reheating.

Reheat: Warm up your soup on the stovetop over medium-low heat until it’s nice and hot, or pop it in the microwave for a quick fix. If you’re using frozen soup, thaw it overnight in the fridge first. Add fresh cheese on top after reheating for the best texture.

Preparation Time	15-20 minutes
Cooking Time	25-30 minutes
Total Time	40-50 minutes
Level of Difficulty	Medium

Estimated Nutrition

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

• Calories: 600-700
• Protein: 35-40 g
• Fat: 15-20 g
• Carbohydrates: 100-110 g

Ingredients

• 1 tablespoon olive oil, extra virgin
• 1 small yellow onion, chopped
• 1 carrot, peeled and chopped
• 2 celery stalks, diced
• 2 cloves garlic, minced
• 1/2 teaspoon crushed red pepper
• 1 teaspoon oregano, dried
• Salt and black pepper to taste
• 28 oz can crushed tomatoes
• 5 cups vegetable broth
• 2 cups water
• 1 bay leaf
• 1 cup uncooked brown lentils
• 2 medium zucchinis, spiralized (noodles trimmed)
• 1/4 cup fresh basil leaves
• Shredded mozzarella cheese for topping (about 1/2 cup)

Step 1: Sauté the Vegetables

Begin by heating oil in a large saucepot over medium-high heat until the oil is shimmering.

Add the chopped onion, carrot, and celery.

Cook these vegetables for 5-7 minutes, or until they sweat and soften.

Add minced garlic, a pinch of red pepper flakes, and a dash of oregano, then season with salt and pepper.

Stir well and cook for an additional minute, or until the mixture is fragrant.

Step 2: Prepare and Simmer the Soup Base

After the vegetables are ready, add crushed tomatoes, vegetable stock, water, bay leaf, and lentils to the pot.

Stir the ingredients together and bring the mixture to a boil.

Once boiling, reduce the heat to medium and let the soup simmer for 15-20 minutes, or until the lentils are fully cooked through.

Step 3: Spiralize and Prepare Zucchini Noodles

While the lentils are cooking, take the time to spiralize the zucchinis using Blade A.

Once spiralized, trim the zucchini noodles using kitchen shears to your desired length for easier eating.

Step 4: Combine Zucchini Noodles and Final Touches

After the lentils are cooked through, stir in freshly chopped basil and the prepared zucchini noodles into the pot.

Allow the soup to cook for an additional 5 minutes, or until the zucchini noodles are al dente, providing a slight bite.

Step 5: Serve the Soup

Ladle the hot soup into bowls and top each serving with a generous amount of mozzarella cheese.

Serve the soup warm, letting the mozzarella gently melt into each bowl.

Enjoy your hearty vegetable lentil soup.