The Best Instant Pot Vegetarian Lasagna Soup
There’s something magical about lasagna without the layering. All those cozy flavors bubbling tomato sauce, garlicky herbs, melty cheese, tender noodles but in a spoonable, no-fuss form that comes together in one pot in well under an hour. This version skips the meat entirely and leans into mushrooms, zucchini, and spinach for texture and heartiness, so it’s just as satisfying as the classic, just lighter on the effort (and the dishes).
If you’ve ever stood in your kitchen staring at a sink full of pots, pans, and a lasagna dish crusted in cheese, you know exactly why this recipe exists. This soup gives you everything you love about lasagna: the layers of flavor, the melty cheese, the tender noodles, without a single extra dish to scrub. Everything happens in your Instant Pot: no boiling noodles in one pot while simmering sauce in another, no assembling layers, no baking dish to soak overnight. Just one pot, one button, and dinner is basically done.
Because it’s brothy instead of baked, this soup naturally has less cheese and oil than a traditional casserole-style lasagna, while still delivering all the same comfort. You’re getting a full serving of vegetables in every bowl mushrooms, zucchini, spinach, carrot, and celery — so it’s a sneaky-good way to eat more veggies without it feeling like a “health food” meal. It’s vegetarian, easy to make gluten-free with your favorite gluten-free noodles, and simple to make vegan with a few swaps (see the notes below). In other words: it tastes like a treat, but it’s actually doing you a favor.
This is the kind of recipe that forgives you. There’s no delicate noodle-boiling timing to worry about, no risk of a soggy or dry lasagna, and no multi-hour prep. You sauté, you dump, you pressure cook, you eat. Most of the actual “work” here is chopping vegetables, and even that takes less than 10 minutes. If you’ve never used your Instant Pot for anything more ambitious than reheating leftovers, this is the recipe that will make you fall in love with it.
Once you make lasagna soup, it’s hard to go back to the layered version — not because it’s not delicious, but because this one gives you 90% of the flavor for about 20% of the effort. It’s the kind of recipe you’ll find yourself making on a random Tuesday just because you can.
Instant Pot Vegetarian Lasagna Soup
A hearty, one-pot spin on lasagna — mushrooms, zucchini, and spinach simmered in a rich tomato broth with broken lasagna noodles, all pressure-cooked together in the Instant Pot, then finished with a dollop of herbed ricotta and a sprinkle of mozzarella. All the cozy flavors of classic lasagna.
Ingredients
- 2 tbsp olive oil
- 1 medium yellow onion, diced
- 2 celery ribs, chopped
- 1 medium carrot, diced
- 8 oz cremini mushrooms, sliced
- 4 cloves garlic, minced
- 2 tbsp tomato paste
- 1½ tsp dried oregano
- 1½ tsp dried basil
- ¼ tsp red pepper flakes
- 28 oz crushed tomatoes (1 can)
- 2 cups marinara sauce
- 4 cups vegetable broth
- 8 oz lasagna noodles, broken into 2-inch pieces
- 1 medium zucchini, diced
- 3 cups baby spinach, roughly chopped
- 1 tsp salt
- ½ tsp black pepper
- 1 cup whole-milk ricotta
- ½ cup grated Parmesan
- ¼ cup fresh basil, chopped, plus more for garnish
- 1 lemon, zested (optional)
- 1 cup shredded mozzarella
Instructions
1. Sauté the base.
Press Sauté on the Instant Pot. Add the olive oil, and once hot, add the onion, celery, and carrot. Cook, stirring occasionally, until softened, about 4 minutes.
2. Cook the mushrooms and garlic.
Add the mushrooms and cook until they release their liquid and start to brown, about 5 minutes. Stir in the garlic, tomato paste, oregano, basil, and red pepper flakes, and cook for 1 minute until fragrant.
3. Add the liquids and noodles.
Press Cancel to stop sautéing. Pour in the crushed tomatoes, marinara, and vegetable broth. Add the salt and pepper. Stir in the broken lasagna noodles, pushing them down to submerge as much as possible — but don't over-stir once they're in.
4. Pressure cook.
Lock the lid and set the valve to Sealing. Press Pressure Cook (Manual) on High Pressure for 4 minutes.
5. Release pressure.
When cooking finishes, quick release by moving the valve to Venting. Once the pin drops, remove the lid.
6. Stir in zucchini and spinach.
Press Sauté again and stir in the zucchini. Cook for 2 minutes until just tender, then stir in the spinach until wilted. Taste and adjust salt and pepper.
7. Make the ricotta topping.
While the soup finishes, stir together the ricotta, Parmesan, chopped basil, and lemon zest in a small bowl.
8. Serve.
Ladle the soup into bowls. Top each with a dollop of the ricotta mixture, a sprinkle of mozzarella, and extra fresh basil.
