Hearty Vegetarian Lasagna Bake (No-Boil Noodles!)
This vegetarian lasagna bake is packed with savory mushrooms, spinach, and creamy ricotta, all layered with no-boil noodles so you can skip the extra pot. It bakes up bubbly and golden in well under an hour.
It’s the kind of dinner that feels special but comes together on a Tuesday, with plenty of leftovers for lunch the next day.
What Makes This Lasagna So Good
The roasted vegetables bring a deep, savory sweetness that balances the tangy tomato sauce, and the no-boil noodles absorb all that moisture, baking up tender without any fuss.
A generous layer of ricotta and mozzarella melts into every bite, giving you those stretchy cheese pulls without an ingredient list a mile long. Even the mushrooms stay meaty and satisfying.
Ingredients
- 2 tbsp olive oil: extra virgin works fine, any neutral oil will do
- 1 medium onion, diced: yellow or white
- 3 cloves garlic, minced: use the fresh stuff, it matters here
- 1 lb cremini mushrooms, sliced: small white mushrooms work too, but cremini hold their texture better
- 1 medium zucchini, diced: about 1½ cups
- 1 red bell pepper, diced: or swap in yellow or orange for a bit more sweetness
- 5 oz fresh baby spinach: if using frozen spinach, thaw and squeeze dry (10 oz package before draining)
- 15 oz whole milk ricotta: part-skim is okay, but the bake will be a little less creamy
- 1 large egg: binds the ricotta so it sets up in the oven
- ½ cup grated Parmesan: plus a little extra for the top if you like a salty crust
- 1 tsp dried Italian seasoning: or a mix of dried oregano and basil
- ½ tsp salt: plus more for the vegetables
- ¼ tsp black pepper: plus more to taste
- 12 no-boil lasagna noodles: you’ll use about 10 to 12; check the box directions, some brands call for a little extra sauce
- 3 cups marinara sauce: one 24 oz jar, choose a brand you really like, because the flavor carries the dish
- 3 cups shredded mozzarella: about 12 oz, low-moisture part-skim melts best
Variations / Substitutions
- Swap the greens: use chopped kale or chard instead of spinach, just sauté it a few extra minutes until tender.
- Use cottage cheese: blend 2 cups full-fat cottage cheese until smooth in place of the ricotta; you may not need the egg then.
- Add a little heat: a pinch of red pepper flakes in the sauce or a layer of jarred Calabrian chilies brightens the whole thing.
- Keep it dairy free: use unsweetened plain almond milk ricotta and a good melting vegan mozzarella alternative.
- Make it more filling: stir a can of rinsed white beans into the sautéed vegetables.
If you like this one, our Mushroom and Spinach Stuffed Shells are another great way to turn those same flavors into a dinner that reheats beautifully.
How to Make Vegetarian Lasagna Bake
Step 1: Sauté the Vegetables
Preheat your oven to 375°F (190°C). Warm the 2 tbsp olive oil in a large skillet over medium heat. Add the diced onion and cook, stirring often, until it softens, about 3 to 4 minutes. Stir in the minced garlic and cook 30 seconds more, just until fragrant, then add the sliced mushrooms, diced zucchini, and diced bell pepper.
Keep the heat at medium and cook the vegetables until they release their liquid and start to brown at the edges, about 8 to 10 minutes. You want the mushrooms to shrink and take on some color, and the zucchini and pepper to lose their raw crunch. Add the spinach in handfuls and stir until it wilts down, 1 to 2 minutes. Season the whole pan with a pinch of salt and pepper, then remove from the heat. The vegetables should taste nicely seasoned but not salty, because the sauce and cheese carry their own salt.
Step 2: Mix the Ricotta Filling
While the vegetables cool a bit, stir together the ricotta, egg, grated Parmesan, Italian seasoning, ½ tsp salt, and ¼ tsp pepper in a medium bowl. Mix until everything is evenly combined and no streaks of egg remain, about 30 seconds. The mixture will be thick and creamy, and it should smell faintly of the herbs.
Step 3: Layer the Lasagna
Spread 1 cup of the marinara sauce across the bottom of a 9×13 inch baking dish. Place 4 of the no-boil noodles over the sauce, overlapping them slightly if they don’t quite fit. Drop half of the ricotta mixture in spoonfuls over the noodles and gently spread it into an even layer. Scatter half of the sautéed vegetables over the ricotta, then sprinkle with 1 cup of the shredded mozzarella and pour on another 1 cup of sauce.
Repeat the layers with 4 more noodles, the remaining ricotta, the remaining vegetables, 1 more cup of mozzarella, and the last cup of sauce. Finish with the final 4 noodles, any sauce left in the jar (scraped clean), and the remaining 1 cup of mozzarella on top. The dish will look tall and packed, which is exactly right.
Step 4: Bake the Lasagna
Cover the dish tightly with foil, spraying the underside of the foil with cooking spray first so it doesn’t stick to the cheese. Bake at 375°F for 25 minutes. Then remove the foil and bake 20 more minutes, until the sauce is bubbling vigorously at the edges and the top cheese is melted and golden in spots.
If you want extra browning on top, you can run the lasagna under the broiler for 2 to 3 minutes, watching it constantly. The no-boil noodles need that covered time to absorb moisture and soften, so don’t rush the first bake.
Step 5: Slice and Serve the Lasagna
Pull the dish out of the oven and let it rest on a cooling rack for 10 minutes. This helps the layers set so they don’t slide apart as soon as you cut in. Slice into 6 squares and use a wide spatula to lift each piece out. Serve hot, with a little extra Parmesan grated over the top if you like.
Tips for Perfect Lasagna Bake
- Use a deep 9×13 dish. A shallow one can overflow once the sauce starts bubbling, and then the bottom of your oven is a mess.
- Don’t skip the foil spray. Gluey cheese stuck to foil is frustrating, and you’ll lose all that top layer.
- If your no-boil noodles seem dry after baking, add ¼ cup of water around the edges before covering and baking next time. Some brands soak up more moisture than others.
- Taste the marinara sauce before you start. If it is bland, the whole bake will be bland, so you can stir in a little salt, dried oregano, or a splash of balsamic vinegar.
Storing and Reheating Leftovers
Refrigerate leftover lasagna in a sealed container within 2 hours of baking, where it will stay good for up to 4 days. The slices actually get firmer and easier to reheat the next day.
For the best texture, reheat covered with foil at 350°F for about 20 minutes, or until warmed through. A microwave works in a pinch but can make the noodles a little soft. You can also freeze the whole baked lasagna (cooled completely) wrapped tightly for up to 3 months; thaw overnight in the fridge before reheating.
What to Serve with Lasagna Bake
A simple green salad with a lemon vinaigrette cuts through the richness of all that cheese and gives you something crisp. Garlic bread rubbed with a raw garlic clove and toasted in the oven turns it into a truly filling meal. Roasted broccoli florets with a squeeze of lemon and a dusting of Parmesan match the bake’s flavor and add a little char on the side.
Frequently Asked Questions
Can I use regular lasagna noodles instead of no-boil?
You can, but boil them to al dente in salted water first, then pat them dry before layering, and reduce the covered bake time to 20 minutes since they don’t need as much moisture.
Is it okay to assemble this the night before?
Yes, assemble the lasagna, cover and refrigerate up to 24 hours ahead. Add 10 to 15 minutes to the covered bake time since you are starting from cold, and watch the top toward the end so it doesn’t over-brown.
How do I keep the lasagna from getting watery?
Squeeze every drop of liquid from frozen spinach if you use it, cook the mushrooms until all their released water evaporates, and stick to the amount of sauce listed; excess liquid from any of these can pool at the bottom.
Can I freeze individual portions?
Absolutely. Cut the cooled lasagna into single servings, wrap each tightly in a layer of plastic wrap and then foil, and freeze for up to 3 months. Reheat from frozen in a 350°F oven for about 25 minutes.
Vegetarian Lasagna Bake Recipe
Ingredients
Method
- Preheat oven to 375°F. Cook onion and garlic in oil until soft, then sauté mushrooms, zucchini, and bell pepper until tender and browned. Add spinach until wilted, season with salt and pepper, and set aside.
- Mix ricotta, egg, Parmesan, Italian seasoning, ½ tsp salt, and ¼ tsp pepper until smooth.
- Spread 1 cup sauce in a 9×13 dish. Layer 4 noodles, half the ricotta, half the vegetables, 1 cup mozzarella, and 1 cup sauce. Repeat with 4 noodles, remaining ricotta, vegetables, 1 cup mozzarella, and 1 cup sauce. Top with last 4 noodles, any remaining sauce, and remaining 1 cup mozzarella.
- Cover with sprayed foil and bake 25 minutes. Uncover, bake 20 minutes until bubbly and golden. Broil 2 minutes if desired.
- Rest 10 minutes, then slice and serve.
