Slow Cooker Lasagna Soup (meatless)

This slow cooker lasagna soup is the perfect high-protein vegetarian and vegan soup to warm you up in the colder months. It’s made with no-boil lasagna in one-pot and can be customized with your favorite vegetables. Gluten-free and Instant Pot options included!

I’m a huge fan of classic Italian lasagna and love it just as much in soup form! It’s so warm, comforting and delicious! Pair it with my Vegan Cheesy Garlic Bread (Pull Apart Bread!) or Vegan Garlic Bread and it might be my favorite meal!

Whether you make this recipe in the pressure cooker or slow cooker, there’s no need to pre-boil the lasagna sheets. A true one-pot lasagna soup either way!

Why Your Family will Love This Lasagna Soup

• Quick and easy. All the delicious flavors of oven baked, layered lasagna, without the work or prep time!
• 1-pot recipe. This lasagna soup is made using no-boil lasagna sheets. Everything cooks directly in the slow cooker or Instant Pot. The perfect dump-and-go recipe for busy families.
• Made dairy-free and vegan. Homemade vegan tofu ricotta helps emulate the cheesy flavors of traditional lasagna without requiring dairy cheese.
• High-protein vegetarian lasagna soup. This lasagna is meatless, but still packs 22 grams of protein per serving. Red lentils and mushrooms are the perfect substitutes for ground beef in a traditional ragù lasagna.

Ingredients You’ll Need

• spices – In addition to garlic and onion powder, I used a blend of dried basil, oregano, and parsley for a homemade Italian seasoning. Substitute 1 tablespoon of a pre-made Italian seasoning.
• miso paste – I love using miso paste to give meals depth and umami. Highly recommend it if you can find it. It’s also a healthier, plant-based substitute for table salt! Either the white miso paste or red miso paste will work well here.
• vegan Worcestershire sauce – Another great ingredient for umami flavor. Annie’s makes my favorite vegan version.
• cremini mushrooms – Great substitute for beef. Can be left out all together if you’re not a mushroom fan.
• red lentils – Adds protein and makes this lasagna hearty! They melt perfectly into the tomato sauce!
• tomato paste and crushed tomatoes – Crushed tomatoes and tomato paste are usually cheaper than marinara sauce and develop so much flavor over 8 hours in the slow cooker.
• vegan beef broth – Can be substituted with vegetable broth, but vegan beef broth is great here!
• no-boil lasagna sheets – Prevents the need to precook your noodles! Most are vegan, just watch out for egg!

How to Make Lasagna Soup

1. Whisk together the broth. In a large bowl or directly in the slow cooker, whisk miso paste, Worcestershire sauce and tomato paste into 5 cups warm vegan beef broth until fully incorporated. This helps ensure the tomato paste and miso paste fully mix into the lasagna soup broth and no clumps sink to the bottom.
2. Mix ingredients into the slow cooker. Add the oil, crushed tomatoes, dried red lentils, sliced mushrooms, spices.

3. Add the broth overtop (unless already whisked in the slow cooker). Stir to combine until evenly distributed and the red lentils are well submerged in the liquid.
4. Slow cook on low. For best results and flavor, set the slow cooker on low and cook for 8 hours. If shorter on time, set the slow cooker to high for 4 hours.

5. Add the lasagna sheets. When the lasagna soup has 20-25 minutes left to cook, break lasagna sheets into smaller pieces and stir into soup. Simmer noodles until al dente, about 20-30 minutes.
6. Serve warm. Serve slow cooker lasagna soup immediately with a dollop of tofu ricotta, vegan mozzarella cheese shreds, nutritional yeast, red chili flakes, and fresh basil, if desired.

Add ins and Variations

• Instant Pot Variation: Full instructions in the recipe card below on how to make this healthy lasagna soup in the Instant Pot. This is a great option if you are super short on time and can be close by to quick-release the pressure.
• Gluten-free option: You can substitute the no-boil wheat lasagna sheets with gluten-free, but they will need to be cooked separately. They don’t cook through very well in the soup – they are a bit gummy. My favorites are the brown rice lasagna sheets by Jovial foods.
• Lower-sodium option: Vegan beef broth can be very salty, depending on the brand. If you are sensitive to sodium or prefer a less salty lasagna soup, use low sodium vegetable broth or use 1-2 cups of water in place of some of the beef broth.
• Add vegetables: I will often make this lasagna soup recipe to use up any leftover vegetables in the fridge. In addition to the 8 ounces of cremini mushrooms, you can add up to 4 cups of additional vegetables. Chopped butternut squash, sweet potatoes, bell pepper, and carrots are all delicious here. Your lasagna soup will be chunkier, but still saucy and soup like.
• No mushrooms option: If you don’t like mushrooms, substitute them with another vegetable, like any of the above listed or one of your favorites!
• Tofu ricotta substitution: I always use my super easy homemade tofu ricotta to top this lasagna soup, but feel free to opt for a store-bought vegan ricotta! Kite Hill and Tofutti both make a store-bought ricotta that are dairy-free.

Expert Tips and Tricks

• Don’t skip the whisking. If you just add the miso paste and tomato paste in, it sinks to the bottom of the slow cooker and won’t flavor the lasagna soup properly.
• How to avoid the burn warning on Instant Pot. If cooking in the Instant Pot, be sure to add the ingredients in the specific order listed in the recipe instructions. This will prevent the lasagna, lentils and tomatoes from burning to the bottom of the pot.

Storage Instructions and How to Freeze

This slow cooker lasagna soup will keep for up to 5 days in the fridge or in the freezer for up to 2 months.

To freeze, allow the lasagna soup to cool completely, then freeze in individual servings using Souper cubes. I like to use the 2 cup individual serving cubes. This allows you to defrost an individual serving and makes it quicker to thaw.

Defrost in the refrigerator until completely thawed, then reheat leftovers in the microwave. Avoid over-heating – this can cause the lasagna sheets to overcook and become too soft!

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Photography by: Baking-Ginger Studios

This recipe was originally published on June 12, 2021 and has been republished on November 26, 2022 to include new recipe photos, helpful tips, add-ins and variations, and freezer instructions. The original recipe remains the same.