Low Carb Lasagna Soup for Weeknights That Crave Comfort

A one-pot, keto-friendly comfort dinner with bold Italian flavor, zucchini noodles, and a ricotta-mozzarella finish—ready in 30 minutes.

Comfort food gets a glow-up when you stop letting noodles run the show. This is the same cozy, cheesy vibe you crave after a long day, minus the carb hangover. You’ll slurp a rich, tomatoey broth loaded with Italian sausage, herbs, and silky zucchini ribbons that play the “pasta” role better than you’d think. The kicker? A cloud of ricotta and melted mozzarella on top that makes every spoonful taste like Sunday supper—on a Tuesday.

If you think low carb means low flavor, this bowl will happily disagree. You’re getting big Italian energy in less time than delivery, and your macros still like you. It’s fast, it’s hearty, and it won’t derail your week—who’s saying no to that?

What Makes This Special

• One-pot wonder: Fewer dishes, more flavor. You build layers like a traditional lasagna, but everything happens in a single pot.
• Ready in 30 minutes: Weeknight-friendly, kid-approved, and you’ll still have time to relax before bed.
• All the lasagna feels: Sausage, fennel, basil, ricotta, mozzarella, and parmesan—aka the flavor dream team.
• Carb-smart comfort: Zucchini ribbons stand in for noodles, so you keep the comfort without the carb crash.
• Customizable: Swap sausage for turkey, use hearts of palm “sheets,” or go dairy-free. Your bowl, your rules.
• Macro-friendly: About 9–12g net carbs per serving, depending on brands and how generous you get with cheese (we see you).

Ingredients Breakdown

• Olive oil: 1 tablespoon for sautéing.
• Italian sausage (mild or hot): 1 pound, casings removed if using links.
• Yellow onion: 1 medium, diced fine.
• Garlic: 4 cloves, minced.
• Tomato paste: 2 tablespoons for depth and body.
• Crushed tomatoes (no sugar added): 1 can (28 oz).
• Beef or chicken broth (low sodium): 4 cups.
• Italian seasoning: 2 teaspoons.
• Fennel seeds: 1/2 teaspoon (signature lasagna sausage note).
• Red pepper flakes: 1/2 teaspoon, or to taste.
• Bay leaves: 2.
• Balsamic vinegar: 1 teaspoon to round the acidity.
• Zucchini: 3 medium, shaved into ribbons (about 4 cups); see tips below.
• Whole-milk ricotta: 1 cup.
• Shredded mozzarella: 1 cup.
• Grated parmesan: 1/2 cup, plus extra for serving.
• Fresh basil: 1/4 cup, chopped, plus more for garnish.
• Kosher salt and black pepper: To taste.
• Optional, for thicker body: 1/4 teaspoon xanthan gum, sprinkled in while simmering (FYI, a little goes a long way).

Instructions

1. Prep your zucchini “noodles”: Use a vegetable peeler to shave long ribbons or a spiralizer for thicker strands. Lay them on paper towels and sprinkle lightly with salt to draw out moisture while you cook.
2. Brown the sausage: Heat 1 tablespoon olive oil in a large pot or Dutch oven over medium-high. Add sausage and cook, breaking it apart, until browned and slightly crispy at the edges, about 5–7 minutes. Drain excess fat if needed, leaving about a tablespoon.
3. Sauté aromatics: Add onion with a pinch of salt. Cook until translucent, 3–4 minutes. Stir in garlic and cook until fragrant, about 30 seconds. Don’t let it burn—bitter garlic is no one’s friend.
4. Build the base: Stir in tomato paste and cook, stirring, until it darkens slightly, 1–2 minutes. This step boosts umami like magic.
5. Deglaze and simmer: Pour in the broth and crushed tomatoes. Scrape up browned bits from the bottom (flavor central). Add Italian seasoning, fennel seeds, red pepper flakes, bay leaves, and balsamic. Bring to a gentle boil, then reduce to a simmer.
6. Simmer and reduce: Let it bubble away uncovered for 12–15 minutes to marry flavors and concentrate the broth. Taste and adjust salt and pepper.
7. Optional thickener: If you want a richer, slightly thicker body, sprinkle in 1/4 teaspoon xanthan gum while whisking. Give it 2–3 minutes to work before adding more. Don’t go heavy—gel-soup is not the vibe.
8. Add zucchini at the end: Stir in the zucchini ribbons and simmer just until tender, 2–4 minutes. Do not overcook or you’ll get mushy strands.
9. Cheese it like lasagna: Off the heat, stir in 1/2 cup mozzarella and 1/4 cup parmesan to enrich the broth. This creates that silky, lasagna-adjacent finish.
10. Plate with ricotta: Ladle into bowls. Dollop each with 2–3 tablespoons ricotta, then sprinkle with remaining mozzarella and parmesan. The residual heat melts everything into glory.
11. Finish and serve: Add chopped basil, a grind of pepper, and a drizzle of good olive oil. Taste one more time; salt fixes flat flavors, but go slow.
12. Optional broil move: For extra drama, portion soup into broiler-safe bowls, add cheese on top, and broil 1–2 minutes until spotty brown. Hello, lasagna vibes.

Storage Instructions

• Fridge: Store soup base and zucchini separately if possible. The base keeps up to 4 days; zucchini ribbons hold 2–3 days.
• Freezer: Freeze the base only (no zucchini, no ricotta) for 2–3 months in airtight containers. Add fresh zucchini and cheeses after reheating.
• Reheat: Warm gently over medium heat until steaming. Add zucchini to the hot soup for 2–3 minutes, then top with ricotta and mozzarella. Microwaving works too; stir halfway so the cheese melts evenly.
• Meal prep tip: Pack ricotta and basil separately so they stay fresh and vibrant. IMO, the fresh basil at the end makes the bowl sing.

Health Benefits

• Lower carbs, higher satisfaction: Zucchini delivers volume with a fraction of the carbs, so you get the “big bowl” feeling without the nap.
• Protein-forward: Sausage, ricotta, and mozzarella provide solid protein that helps with satiety and muscle repair. Swap in turkey sausage for even leaner macros.
• Micronutrient boost: Tomatoes bring lycopene; basil adds antioxidants; zucchini contributes potassium and vitamin C. Small choices add up.
• Sodium control: Use low-sodium broth and salt to taste. You control the seasoning, not a jarred sauce.
• Balanced fats: Dairy gives satisfying fats that help flavors bloom. Choose part-skim ricotta if you prefer a lighter bowl.

Pitfalls to Watch Out For

• Overcooking zucchini: It goes from al dente to soggy fast. Add it at the end and pull the pot off heat promptly.
• Sugary tomatoes: Check labels. Choose no-sugar-added crushed tomatoes and skip sweet marinara.
• Watery bowl: Salt zucchini lightly and blot. Simmer the base uncovered to reduce before adding veg.
• Curdled dairy: Don’t boil after adding cheese. Fold it in off heat for a smooth, luxe finish.
• Flat flavor: Salt in layers—sausage, onions, then the pot. Finish with acid (balsamic) and fresh basil to pop the flavor.
• Heavy xanthan: Sprinkle lightly while whisking. Too much and you’ll think you made gravy by accident (you didn’t, but still).

Mix It Up

• Cabbage “noodles”: Thinly slice green cabbage and simmer 5–7 minutes for a heartier bite and excellent leftovers.
• Hearts of palm sheets: Cut hearts of palm lasagna sheets into strips and add in the last 3 minutes.
• Meatless magic: Swap sausage for 8 oz cremini mushrooms (browned hard) and a splash of soy or coconut aminos for umami.
• Spicy arrabbiata: Double the red pepper flakes and add 1 teaspoon Calabrian chili for heat-lovers.
• Dairy-free: Use almond ricotta, skip mozzarella, and finish with 2–3 tablespoons nutritional yeast for savory depth.
• Higher protein: Stir 1/2 cup cottage cheese into the pot off heat and blend partially for a creamy, protein-packed base (FYI, it won’t taste “cottagey”).
• Instant Pot: Sauté sausage, onion, garlic; add liquids and spices; pressure cook 5 minutes (quick release), then add zucchini on sauté for 2–3 minutes.
• Slow cooker: Brown sausage and aromatics first, then cook on LOW 4–5 hours. Stir in zucchini during the last 20 minutes, then add cheeses.

FAQ

How do I keep the soup from getting watery?

Salt and blot the zucchini, then add it at the end. Let the base simmer uncovered to reduce before the veg goes in. If needed, whisk in a pinch of xanthan gum to body it up—just a pinch, promise.

Can I make this without sausage?

Absolutely. Use ground turkey, chicken, or beef, or go meatless with browned mushrooms. Add a splash of soy or coconut aminos and extra fennel to keep that savory lasagna signature.

How many carbs are in a serving?

With no-sugar-added tomatoes and zucchini “noodles,” you’re looking at roughly 9–12g net carbs per serving. Brands vary, and cheese portions matter, so check your labels to be precise.

Will this freeze well?

Freeze the base only for best texture. Dairy and zucchini don’t love the deep freeze. Reheat the base, then add fresh zucchini and your ricotta-mozzarella combo for a just-cooked feel.

Can I use cottage cheese instead of ricotta?

Yes. Blend cottage cheese until smooth for a ricotta-like texture, or stir it in off heat for extra protein. Season with a pinch of salt and parmesan to boost flavor.

How can I thicken the soup without flour or starch?

Reduce the base longer, melt in extra parmesan, or use a tiny amount of xanthan gum. You can also purée a cup of the soup and stir it back in. Easy win.

Is this gluten-free?

Yes, assuming your sausage, broth, and canned tomatoes are certified gluten-free. Check labels—gluten sneaks into spice blends and processed meats sometimes.

What if I don’t have fennel seeds?

Skip them or add a little more Italian seasoning. Fennel amplifies the classic sausage-lasagna flavor, but the soup still slaps without it (IMO).

Wrapping Up

This bowl gives you the big, cheesy Italian comfort you want with a carb count your goals can handle. It’s fast, flexible, and absolutely weeknight-proof. Stock a few pantry staples, grab some zucchini, and you’re about 30 minutes from a spoonful of cozy. Leftovers tomorrow? Even better—because you deserve a win two days in a row.