Vegetable Lasagna Recipe

I developed a Vegetarian Lasagna Recipe with spinach and zucchini that uses a simple casserole shortcut perfect for meal prep and tends to win over even meat eaters.

I make this Garden Vegetable Lasagna when I want dinner that looks like effort but really isn’t. Zucchini and spinach give each slice a surprising bite, and the flavors somehow stack so youre curious by the second forkful.

It’s my go-to Easy Vegetable Lasagna for nights I need to feed a crowd, and people actually call it a Vegetarian Casserole they prefer over meat dishes. I won’t pretend I get it perfect every time, I mess up the layers now and then, but that little imperfection is why folks keep sneaking another piece.

Ingredients

• Zucchini: Mild and slightly sweet, adds fiber and moisture, keeps the lasagna light and fresh
• Spinach: Earthy iron rich leafy green, packs fiber, vitamins and a silky wilted texture
• Ricotta: Creamy mild cheese that adds protein and calcium while smoothing the bite
• Mozzarella: Soft and melty brings gooey stretch and moderate fat for rich comforting bites
• Mushrooms: Umami packed and low calorie, they add a meat like chew and depth
• Marinara sauce: Tomato based, tangy with a hint of sweetness, supplies vitamin C and lycopene
• Onion and garlic: Essential aromatics that build savory flavor, tiny carbs but big taste impact
• Parmesan and basil: Parmesan adds salty umami and calcium, basil lifts with fresh peppery brightness

Ingredient Quantities

• 9 lasagna noodles (regular)
• 3 cups marinara sauce
• 2 tbsp olive oil
• 1 medium yellow onion, chopped
• 3 garlic cloves, minced
• 2 medium zucchini (about 1 lb), sliced
• 8 oz cremini or button mushrooms, sliced
• 10 oz fresh baby spinach (or 1 10-oz package)
• 1 (15 oz) container ricotta cheese
• 1 large egg
• 2 cups shredded mozzarella cheese (about 8 oz)
• 1/2 cup grated parmesen cheese
• 1/4 cup fresh basil, chopped
• 1 tsp dried oregano
• 1 tsp salt
• 1/2 tsp black pepper
• 1/4 tsp red pepper flakes (optional)

How to Make this

1. Preheat oven to 375 F and bring a large pot of salted water to a boil, cook the 9 lasagna noodles until al dente (follow package time), drain and lay flat on a clean towel so they dont stick.

2. Heat 2 tbsp olive oil in a large skillet over medium heat, add the chopped yellow onion and cook until soft, add the minced garlic and cook 30 seconds more.

3. Add the sliced zucchini and mushrooms, cook until browned and most of the moisture is gone, then stir in 1 tsp dried oregano, 1 tsp salt, 1/2 tsp black pepper and the 1/4 tsp red pepper flakes if using.

4. Add the baby spinach in batches, cook just until wilted, then remove the pan from heat and squeeze out any excess liquid from the veggies with a spatula or by pressing through a colander.

5. In a bowl combine the 15 oz ricotta, the large egg, 1/4 cup grated parmesan, 1/4 cup chopped fresh basil, and a little extra black pepper to taste, mix until smooth.

6. Spoon about 1/2 cup of the marinara sauce into the bottom of a 9×13 baking dish to prevent sticking.

7. Assemble: place 3 noodles in a single layer, spread about one third of the ricotta mixture over them, top with one third of the veggie mixture, spoon some marinara, and sprinkle about one third of the shredded mozzarella. Repeat two more times so you have three noodle layers, finishing with sauce and the remaining mozzarella and the remaining grated parmesan on top.

8. Cover the dish tightly with foil and bake for 25 minutes, then remove the foil and bake another 10 to 15 minutes until the cheese is bubbly and lightly browned.

9. Let the lasagna rest 10 to 15 minutes before slicing so it sets up and doesnt run, this also makes it easier to serve and great for meal prep.

10. Garnish with the remaining chopped basil if you like, cut into squares and enjoy warm, leftovers reheat really well.

Equipment Needed

1. Oven (preheat to 375 F)
2. Large pot (for boiling the lasagna noodles)
3. Colander (drain noodles and press out veggie liquid)
4. Large skillet or sauté pan (for the onion, zucchini, mushrooms & spinach)
5. 9×13 baking dish (to assemble and bake the lasagna)
6. Mixing bowl (to combine ricotta, egg, parmesan and basil)
7. Measuring cups and measuring spoons (for sauce, cheese and spices)
8. Chef’s knife (chop onion, garlic, zucchini and basil)
9. Cutting board
10. Rubber spatula or wooden spoon (spread mixtures and scrape bowls)

FAQ

Vegetable Lasagna Recipe Substitutions and Variations

• Lasagna noodles (regular)
  • No-boil (oven-ready) noodles, they cook in the sauce so add a bit more sauce.
  • Thinly sliced zucchini or eggplant, overlap slices to make “noodle” layers, pat them dry so it doesnt get soggy.
  • Gluten-free lasagna sheets, either pre-cooked or no-boil depending on the brand.
• Ricotta cheese
  • Cottage cheese, pulse/blend briefly for a smoother texture.
  • Crumbled firm tofu mixed with a splash of lemon juice and nutritional yeast for a vegan option.
  • Cashew “ricotta” (soaked cashews blended with lemon and salt) if you want dairy free and creamy.
• Baby spinach
  • Baby kale or Swiss chard, cook a little longer until tender.
  • Frozen chopped spinach, thawed and squeezed dry so it doesnt water down the lasagna.
  • Arugula for a peppery bite, add only a little since it wilts fast
• Shredded mozzarella
  • Provolone or fontina, they melt nicely and give a richer flavor.
  • Monterey Jack, good if you want extra melty stretch.
  • Vegan shredded mozzarella for a dairy free version, check melting notes on the package.

Pro Tips

1) Squeeze the veggies till theyre almost dry. Even if you cooked off most moisture, put the veggies in a colander and press with the back of a spoon or wrap in a clean towel and squeeze. If zucchini seems watery you can salt it, let it sit 10 minutes, then squeeze — less watery lasagna, not a soggy mess.

2) Taste and season every layer. The ricotta mix should taste good on its own, add more salt, pepper or a pinch of nutmeg if it feels flat. Same with the veggies, season while theyre hot so the flavors actually develop.

3) Save a little pasta water and dont overcook noodles. A splash of reserved pasta water helps the sauce cling if it seems dry, and undercooking the noodles by a minute or so keeps them from getting mushy after baking.

4) Rest, slice, and freeze smarter. Let the lasagna cool and sit 15 to 20 minutes or longer before cutting so it sets up and doesnt run. For meal prep, cool fully, wrap tightly and freeze in portions; reheat covered at a moderate temp so it heats through without drying out. If you want a browned top at the end, broil for 1 to 90 seconds but watch it closely or youll burn it.