Vegetarian Spinach and Mushroom Lasagna

DinnerCasseroleVegetarianLasagna

Vegetarian Lasagna to feed a crowd! This one is filled with meaty shiitake and cremini mushrooms, spinach, and ricotta and Mozzarella cheeses. Your vegetarian and meat-eating guests will fight for seconds.

Photography Credit: Elise Bauer

Pot Luck? Big Crowd? Consider a Veggie Lasagna

Have a large crowd gathering for the holidays? Did you sign up to bring a main dish to a potluck feast? Consider this veggie lasagna. It’s hearty, filling, and feeds a multitude.

Be warned, though. This vegetarian spinach and mushroom lasagna is so good your guests may ask for it again and again — for every potluck, for every holiday feast. They’ll get those puppy dog eyes when they look at you and say, “Oh, how about that veggie lasagna, it’s so good, and everyone can eat it—could you bring that?”

And you’ll be slightly annoyed because, perhaps you were hoping to squeeze by with a simple potato salad, even though you signed up for a main. But then you’ll think about how good this lasagna is and how much you want some too, and then it’s just an excellent excuse to make it again.

Vegetarian Spinach Mushroom Lasagna

Vegetarian Lasagna For All

Now, you may ask, why a vegetarian lasagna? A veggie lasagna can be especially helpful around holiday meals when you are trying to figure out what to serve cousin Judy and uncle Joe who won’t eat turkey, goose, roast beef, or whatever the main meat dish is of the meal.

It’s doubly helpful the days after the big feast when you still have friends and relatives around who need to be fed, and you don’t want to serve leftover turkey for every meal.

This vegetarian lasagna fits that bill, too, in that it is so filled with meaty shiitake and cremini mushrooms, spinach, and ricotta and Mozzarella cheeses, your meat-eating guests will be fighting for seconds along with the vegetarians.

Hopefully, they’ll remember to leave some for you!

Elise Bauer with Vegetarian Spinach Mushroom Lasagna

Lasagna Prep Tips

  • Start by boiling the water for the noodles and defrosting the spinach.
  • Prep the mushrooms and cheeses while the water boils and spinach defrosts.
  • Use high quality tomato sauce, such as this Muir Glen crushed tomatoes with basil.
  • You can prep this lasagna the night before, keep it covered in the fridge, and bake it the day you want to serve it.

HOW TO STORE AND REHEAT LEFTOVERS

Lasagna makes great leftovers! You can keep this lasagna in the refrigerator for at least 5 days. Warm up slices in the microwave, or reheat the entire lasagna (covered with foil) in a 350°F oven until the cheese is bubbly.

  • For more information about storing and freezing, see our Lasagna recipe.

LOVE LASAGNA? HERE ARE 5 MORE:

Updated September 19, 2019 : We spiffed up this post to make it sparkle. No changes to the original recipe.

Vegetarian Spinach and Mushroom Lasagna Recipe

  • Prep time: 20 minutes
  • Cook time: 1 hour, 45 minutes
  • Yield: Serves 8-10

The first thing I do to start making this recipe is to get a big pot of salted water heating for the pasta, and defrost the spinach. While this is happening you can prep the mushrooms and cheeses.

Use high quality tomato sauce for best results.

If fresh basil is not available for layering in the casserole, add 2 teaspoons of dried basil to the sauce.

Ingredients

For the sauce:

  • 1 1/2 pound cremini mushrooms, roughly chopped
  • 1/2 pound shiitake mushrooms, roughly chopped
  • Salt
  • 1 generous cup chopped onions
  • 1/4 cup extra virgin olive oil plus more for keeping the noodles from sticking to each other
  • 4 cloves garlic, chopped (about 4 teaspoons)
  • 1 (6-ounce) can tomato paste
  • 2 cups tomato sauce
  • 1 (28-ounce) can crushed tomatoes (such as Muir Glen with basil)
  • 1 cup water
  • 1 tablespoon dried thyme
  • 1/2 teaspoon red pepper flakes
  • 1 tablespoon sugar

For the lasagna:

  • 2 (10-ounce) boxes frozen chopped spinach, thawed and squeezed in clean towel of excess moisture
  • 1 pound lasagna noodles (16 to 20 noodles)
  • 1 (15-or-16-ounce) container of ricotta cheese
  • 1/4 cup chopped fresh basil
  • 1/4 pound pecorino cheese (or Parmesan), grated (about 1 cup)
  • 1 pound shredded mozzarella cheese (about 4 cups)

Special equipment:

Method

1 Sauté the mushrooms: Place mushrooms in a large (6 to 8 quart) sauté pan on high or medium high heat. Stir them with a wooden spoon or shake the pan from time to time. You may hear them squeak.

Sprinkle salt over the mushrooms. The mushrooms will sizzle and then start to release water. (Note that you are not adding fat at this point to the pan; this method of cooking mushrooms in their own moisture is called "dry sautéing.)

Once the mushrooms start to release water into the pan, stir in the chopped onions. Cook until the mushrooms are no longer releasing moisture and the mushroom water has boiled away, about 5 minutes more.

2 Make the sauce: Add the olive oil to the mushrooms and stir to coat. Sauté the mushrooms and onions for about a minute. Add the garlic and cook for another minute.

Stir in the tomato paste, cook for a minute longer. Reserve 1 cup of the tomato sauce (it will go in the bottom of the casserole dish), and put the remaining cup of tomato sauce into the pot with the mushrooms.  Add the large can of crushed tomatoes and one cup of water.

Stir in the thyme, sugar, and red pepper flakes. (If you are using dried basil instead of fresh, add it now.) Bring to a simmer, then lower the heat and simmer on a low simmer, for 20 minutes.

3 Boil and drain the lasagna noodles: Once the sauce is simmering, salt the boiling pasta water, and add the dry lasagna noodles to the boiling water.  (The water should be at a vigorous, rolling boil.) Stir gently, making sure that the noodles are not sticking to each other. Set the timer for 8 minutes, or however long is indicated on the package of the noodles. Cook uncovered on a high boil.

When the noodles are ready (al dente, cooked through but still firm to the bite), drain the noodles in a colander, and rinse them to cool them with cold water.  As you rinse them, gently separate them with your fingers so they don't stick to each other.

Prepare a couple large cookie sheets or baking sheets by spreading a tablespoon of olive oil over the baking sheets.

Place the lasagna noodles on the sheets, gently coating them with a bit of that olive oil, and spreading them out. This will help keep them from sticking to each other while you finish the sauce and prepare the layered casserole.

4 Assemble the lasagna: Turn off the heat on the stovetop for the sauce. Preheat the oven to 350°F.

Spread the one cup of reserved tomato sauce over the bottom of a large (preferably 10x15-inch) casserole dish. (If your casserole dish is smaller, you may need to add another layer as you go through this step.)

Place a layer of lasagna noodles down over the tomato sauce, slightly overlapping. (For our 10x15-inch dish, we ultimately fit 3 layers of 6 noodles each, with 2 extra noodles on which to nosh.)

Sprinkle half of the ricotta cheese over the noodles, and half of the defrosted, drained, and squeezed out spinach over the ricotta.

Sprinkle half of the mozzarella cheese over the spinach, and just a quarter of the pecorino cheese.

Then spoon 1/3 of your mushroom sauce over the mozzarella. Sprinkle half of the fresh basil over the sauce.

5 Repeat layers: Repeat the layering process. Place a second layer of noodles over the sauce. Spread the remaining ricotta, spinach, and mozzarella over the noodles. Sprinkle another quarter of the pecorino along with the mozzarella. Top with another third of the mushroom sauce and the remaining fresh basil.

Layer your final layer of lasagna noodles over the sauce. Spread the remaining sauce over the lasagna noodles, and sprinkle with the remaining pecorino or parmesan cheese.

6 Cover with foil and bake: Pull out a sheet of aluminum foil large enough to cover the casserole dish. Spread a little olive oil over the inside of the piece of foil (the side that will have contact with the lasagna). Place the foil over the casserole dish and crimp the edges.

Bake at 350°F for 25 minutes, then remove the foil and bake uncovered for an additional 25 minutes.

Take the lasagna out of the oven when done and let it rest 10 minutes before cutting to serve. Once made, the lasagna will last a week in the fridge.

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Elise Bauer

Elise Bauer is the founder of Simply Recipes. Elise launched Simply Recipes in 2003 as a way to keep track of her family's recipes, and along the way grew it into one of the most popular cooking websites in the world. Elise is dedicated to helping home cooks be successful in the kitchen. Elise is a graduate of Stanford University, and lives in Sacramento, California.

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118 Comments / Reviews

No ImageVegetarian Spinach and Mushroom Lasagna

Did you make it? Rate it!

  1. Darrell

    By far the best lasagna I’ve made, and tasted for that matter. Definitely worth every bit of the time it takes to make it.

    xxxxxyyyyy

  2. Alice

    This needed more salt in my opinion. Unless I missed it, the only added salt is to the mushroom sauté . Its a shame because it is a beautiful lasagna.

    xxxxxyyyyy

  3. Mimi

    This is a wonderful recipe. I doubled it and had enough room for an extra layer in an industrial pan. I was serving a group of 15, and there were no leftovers. I did use fresh spinach, cooked and drained, as I had a lot around.

    xxxxxyyyyy

  4. Terrence

    I love this recipe. My whole family loves it too. Fresh spinach works well with it.

    xxxxxyyyyy

  5. james

    I forgot to add, I use fresh spinach

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