The first time I made this Vegetarian Lasagna Soup it felt like someone turned lasagna into a cozy bowl of comfort food.
It hits all the familiar notes—tomato, garlic, cheese—but it’s faster and way easier to serve to a crowd.
This recipe is a weeknight winner: pantry-friendly, forgiving, and loudly satisfying without meat.
Why You’ll Love This Recipe
- Comforting lasagna flavor in a spoonable form that’s faster than assembling a pan.
- Pantry-stable lentils add body and protein so the soup feels substantial.
- One-pot cleanup with pasta cooked straight in the broth.
- Flexible: easy to make vegan or swap cheeses for a lighter version.
The texture walks a lovely line between brothy and hearty. The split red lentils break down slightly as the soup simmers, thickening the broth and giving a comforting grainy body that mimics the bite of ground meat. The broken lasagna noodles provide chewy pasta ribbons that soak up tomatoey broth, while dollops of ricotta and shredded mozzarella create creamy pockets and a melty finish on top.
"Absolutely addictive — my kids called it lasagna in a bowl. Ready in 40 minutes and so flavorful!" — Claire, reader
Key Ingredients
Split red lentils
Split red lentils are the unsung hero here. They cook quickly and naturally thicken the broth as they soften, so you get a meaty mouthfeel without any animal product. Look for red lentils in the bulk or dried beans aisle; they don’t need pre-soaking and will melt into the soup texture during the simmer.
Fire-roasted crushed tomatoes (canned)
Fire-roasted tomatoes add a subtle char and depth that keeps the soup from tasting flat. Using the crushed texture gives body and helps the lentils blend into the broth; choose a brand with minimal added sugar and salt for better control.
Basil pesto
Pesto is a concentrated hit of basil, garlic, and olive oil that brightens the entire pot. Stirring in pesto near the start layers fresh herbal flavor without relying on fresh basil quantity. A good jarred pesto (or homemade) makes the soup sing — I often use a basil-forward store brand for consistency.
Lasagna noodles (broken)
Using broken lasagna noodles gives the soup those classic broad noodle ribbons that feel like lasagna sheets. Break them into bite-sized pieces so they cook evenly in the pot. Traditional dried lasagna noodles work fine; no need for no-boil noodles here because they cook directly in the broth.
Full ingredient list:
- 1 tablespoon olive oil
- 1 yellow onion, diced
- 6 cloves garlic, thinly sliced
- 1.5 tablespoons Italian seasoning
- 2 tablespoons tomato paste
- 1/2 cup basil pesto
- 1/2 cup uncooked split red lentils
- 2 (28 oz.) cans fire roasted crushed tomatoes
- 4 cups vegetable broth
- 1-2 teaspoons granulated sugar, optional
- 8 uncooked lasagna noodles, broken into bite sized pieces
- 2-3 cups chopped fresh baby spinach, optional
- 1/2 cup Parmesan cheese
- 1/2 cup shredded mozzarella cheese
- 1 cup whole milk ricotta cheese
- Fresh chopped parsley for garnish
- Kosher salt
- Fresh cracked pepper
Step-by-Step Instructions
Step 1: Sauté aromatics
Heat the olive oil in a large pot over medium-high heat.
Add the diced onion with a pinch of salt and freshly cracked pepper. Sauté, stirring frequently, about 3 minutes until the onion is soft and translucent.
Pro Tip: The onion should be glossy and just starting to brown around the edges — that light browning adds flavor.
Step 2: Add garlic and herbs
Reduce heat to medium. Add the thinly sliced garlic and Italian seasoning along with a couple pinches of salt and pepper. Sauté for another minute until fragrant.
Pro Tip: Watch the garlic closely; it should sizzle gently but not brown, or it will taste bitter.
Step 3: Cook the tomato paste
Stir in the tomato paste and cook for about 2 minutes. Keep stirring until the paste deepens to a brick-red color and becomes fragrant.
Pro Tip: The color change is your cue — the caramelized paste adds a toasty umami base that elevates the whole soup.
Step 4: Deglaze and combine the base
Deglaze the pot with a splash of vegetable broth, scraping up any browned bits from the bottom. Then add the pesto, split red lentils, crushed tomatoes, and the rest of the vegetable broth. Add sugar if using, and season with a few large pinches of salt and pepper.
Pro Tip: The deglaze step lifts concentrated flavor from the bottom; don’t skip it even if the pan looks clean.
Step 5: Bring to a gentle simmer
Turn the heat up to medium-high and bring the mixture to a gentle simmer. Stir occasionally as it comes to a simmer so the lentils don’t stick to the bottom of the pot.
Pro Tip: You want small bubbles—not a rolling boil—so the lentils cook evenly without breaking apart too aggressively.
Step 6: Add noodles and finish cooking
Stir in the broken lasagna noodles. Reduce heat to low or medium-low and simmer gently for 12–15 minutes until the pasta is al dente and the lentils are tender. Stir occasionally so noodles and lentils don’t cling to the pan.
Pro Tip: Test a noodle piece at 10 minutes; cooking times vary by brand, and you want a slight bite so it won’t go mushy later.
Step 7: Add greens and season
Remove the pot from heat and stir in the chopped baby spinach until it wilts. Taste and adjust salt and pepper.
Pro Tip: Add spinach off heat to preserve its color and tender texture.
Step 8: Top with cheeses and serve
Ladle the soup into bowls and top with grated Parmesan, shredded mozzarella, and a generous dollop of ricotta. Put the lid back on the pot (or cover each bowl) for a few minutes to let the cheese melt. Garnish with fresh parsley and serve.
Pro Tip: Letting the pot rest with a lid melts the cheese into gorgeous ribbons; the ricotta dollop gives you creamy pockets in every spoonful.
Expert Tips for Success
- Use low to medium heat when simmering. A gentle simmer cooks lentils and noodles evenly without falling apart. If you see rapid boiling, lower the heat immediately to avoid a broken texture.
- Salt strategically. Add a couple large pinches when you add the broth and again after the pasta cooks. Canned tomatoes vary in salt content, so taste before oversalting.
- Watch the lentils. Split red lentils cook quickly and will soften to create body. If they begin to dissolve too much, reduce the heat and finish cooking sooner.
- Pasta timing matters. Different lasagna noodles vary in thickness; check the pasta at 10 minutes and then every 2 minutes to achieve al dente. Overcooked noodles will make the soup gummy after storing.
- Swap part of the broth for rich tomato juice. If you prefer a more tomato-forward profile, replace 1 cup of vegetable broth with good-quality low-sodium tomato juice for extra depth.
- Finish with acid. If the soup tastes flat after simming, a teaspoon of balsamic vinegar or a squeeze of lemon brightens flavors without adding sugar.
- Cheese technique: Use whole-milk ricotta for creaminess and a balance of shredded mozzarella to melt. If you want sharper flavor, stir in 1/4 cup grated Pecorino with the Parmesan.
- Use an immersion blender carefully. If you want a thicker stew-like consistency, pulse the soup briefly with an immersion blender before adding noodles. Don’t overblend; you want texture from both lentils and noodles.
- Double-batch for gatherings. The flavors deepen the next day, so this is perfect for making ahead — but follow storage tips to keep noodle texture intact.
- Pan size: Start in a wide, heavy-bottomed pot. A wide pot gives more surface area for evaporation and for noodles to spread rather than clump.
Storage & Freezing
Fridge storage: Cool the soup to room temperature within an hour and transfer to airtight containers. Store in the refrigerator up to 4 days. Reheat gently on the stovetop over low heat, adding a splash of vegetable broth if the soup has thickened, and stir frequently to prevent sticking.
Freezer storage: For best results freeze without added fresh spinach or mozzarella toppings. Cool completely, then portion into freezer-safe containers leaving a little headspace. Freeze for up to 3 months. Thaw overnight in the refrigerator before reheating.
Reheating from frozen: Thaw in the fridge overnight, then reheat on the stovetop over low heat until simmering. Add a splash of broth and stir in fresh spinach at the end. If pasta has absorbed too much liquid after freezing, revitalize the soup with 1/2 to 1 cup of hot broth while stirring.
Avoid refreezing: Repeated freeze-thaw cycles degrade both lentils and pasta texture. Only freeze once for best texture.
Variations & Substitutions
Cheesy vegetable boost: Stir in roasted red peppers or chopped roasted zucchini near the end for added sweetness and texture. Top with fresh basil instead of parsley for a peppery finish.
Vegan swap: Replace the cheeses with a dollop of cashew ricotta or silken tofu blended with nutritional yeast and lemon. Use a vegan pesto or omit pesto and add extra basil and a splash of olive oil.
Meaty alternative: If you aren’t vegetarian, brown 8 ounces of ground turkey or plant-based crumbles in the pot after the onion step, then proceed with the recipe for a heartier, meat-forward version.
Gluten-free version: Use gluten-free lasagna noodles broken into pieces or sub small gluten-free pasta shapes. Watch cooking times closely as many gluten-free pastas cook differently and can go mushy if overcooked.
Frequently Asked Questions
Q: Can I make this soup in a slow cooker?
A: Yes, but adjust the pasta timing. Brown the onions and garlic on the stovetop, then transfer everything except the lasagna noodles and spinach to the slow cooker. Cook on low 4–6 hours. Add broken noodles and spinach for the last 30–40 minutes, or cook noodles separately and combine at serving to avoid mushy pasta.
Q: Can I use brown lentils or green lentils instead of red?
A: You can, but brown and green lentils hold their shape and won’t dissolve into the broth like red lentils. If you prefer intact lentils, increase simmer time for tenderness and expect a chunkier texture rather than a thickened broth.
Q: Why is my soup too thin or too thick?
A: Thin soup usually needs more simmering or additional lentils/pasta to thicken. Too thick often comes from pasta and lentils absorbing liquid; thin with extra vegetable broth or water and reheat gently. Adjust seasoning after modifying consistency.
Q: Can I prepare the base ahead and add noodles later?
A: Absolutely. Cook the base with lentils and tomatoes, cool, and refrigerate. When ready to serve, reheat and add broken lasagna noodles, simmering until al dente, then stir in spinach and cheeses.
Q: How do I prevent the noodles from sticking together?
A: Stir the pot after adding noodles and every few minutes while they cook. Using a wide pot helps distribute noodles. If they start to clump, add a splash of broth and stir to separate.
Final Thoughts
This Vegetarian Lasagna Soup is proof that comfort classics can be simplified without losing soul. It’s forgiving, freezer-friendly, and endlessly adaptable.
Please leave a star rating in the recipe card below and pin this to your favorites on Pinterest so others can find it.
Conclusion
If you want to explore a slightly different take with garden vegetables, this Garden Vegetable Lasagna Soup Recipe – Budget Bytes is a great companion to compare flavors and techniques.
For a slow-cooker version to set and forget, check out this handy Vegetarian Slow Cooker Lasagna Soup (Super Easy!) – foodiecrush which adapts the concept to a longer, low-and-slow cook.
Vegetarian Lasagna Soup
Ingredients
For the soup base
- 1 tablespoon olive oil For sautéing
- 1 medium yellow onion, diced Adds sweetness and flavor
- 6 cloves garlic, thinly sliced Adds aroma and depth
- 1.5 tablespoons Italian seasoning Herb blend for flavor
- 2 tablespoons tomato paste For depth of flavor
- 0.5 cup basil pesto Brightens the soup
- 0.5 cup uncooked split red lentils Thickens the broth
- 2 cans (28 oz.) fire roasted crushed tomatoes Provides the tomato base
- 4 cups vegetable broth For the soup base
- 1-2 teaspoons granulated sugar, optional To balance acidity
For the pasta and toppings
- 8 pieces uncooked lasagna noodles, broken into bite-sized pieces Classic pasta element
- 2-3 cups chopped fresh baby spinach, optional Add freshness and nutrients
- 0.5 cup Parmesan cheese For grating on top
- 0.5 cup shredded mozzarella cheese For melting into the soup
- 1 cup whole milk ricotta cheese Adds creaminess
- to taste Kosher salt For seasoning
- to taste Fresh cracked pepper For seasoning
- Fresh chopped parsley for garnish To add color and flavor
Instructions
Preparation
- Heat the olive oil in a large pot over medium-high heat.
- Add the diced onion with a pinch of salt and freshly cracked pepper. Sauté, stirring frequently, about 3 minutes until the onion is soft and translucent.
- Add the thinly sliced garlic and Italian seasoning along with a couple pinches of salt and pepper. Sauté for another minute until fragrant.
Cooking the base
- Stir in the tomato paste and cook for about 2 minutes, until the paste deepens to a brick-red color.
- Deglaze the pot with a splash of vegetable broth, scraping up any browned bits from the bottom. Then add the pesto, split red lentils, crushed tomatoes, and the rest of the vegetable broth.
- Add sugar if using, and season with a few large pinches of salt and pepper.
Simmering
- Turn the heat up to medium-high and bring the mixture to a gentle simmer.
- Stir occasionally as it comes to a simmer so the lentils don’t stick to the bottom.
- Stir in the broken lasagna noodles. Reduce heat to low or medium-low and simmer gently for 12–15 minutes until the pasta is al dente and the lentils are tender.
Final Steps
- Remove the pot from heat and stir in the chopped baby spinach until it wilts.
- Taste and adjust salt and pepper.
- Ladle the soup into bowls and top with grated Parmesan, shredded mozzarella, and a generous dollop of ricotta.
- Garnish with fresh parsley and serve.
