Summer Squash and Portobello Mushroom Vegetarian Lasagna – Recipe


My previous spinach and ricotta vegetarian lasagna recipe has consistently been one of the most popular on the site, so I thought I’d share another variation with you. This versions adds layers of thinly sliced summer squash (or zucchini) and portobello (aka portabella, portabello) mushrooms.


The key to making this lasagna great is that both vegetables are thoroughly sauteed first to maximize flavor and minimize any sort of watery outbursts. See the picture at right – maybe I went a bit too far, but you really want to caramelize the surfaces.

When I told my brother I was making this, he asked a very good question: “Are portobellos even relevant anymore?” I knew what he meant. They are one of the most often overused and abused cliches in the vegetarian repertoire, because they are thought to be a good stand-in for meat. I probably don’t cook with them more than a couple of times per year, but I think that properly prepared they have a good flavor and texture. I like to lay the caps down flat and slice them on the bias, a trick I learned at Cafe Flora while making untold hundreds of Wellingtons and French Dips.

Summer Squash and Portobello Mushroom Vegetarian Lasagna

Prep Time: 30 minutes

Cook Time: 1 hour

Yield: Serves at least 8

Summer Squash and Portobello Mushroom Vegetarian Lasagna

  • 6 medium crookneck or other summer squash or zucchini, sliced lengthwise, 1/8" thick
  • 6 large portobello mushroom caps, sliced 1/8" thick on a bias
  • extra virgin olive oil for sauteeing
  • 1 lb. ricotta
  • 2 eggs
  • 1/2 teaspoon nutmeg
  • 1 onion, diced
  • 2 cloves garlic, minced
  • 2 large (28 oz.) cans plain tomato sauce
  • zest from 1 lemon
  • 1.5 pounds no-boil lasagna noodles (or regular lasagna noodles, par-boiled)
  • salt, pepper to taste
  • 1 lb. grated mozzarella
  • 4 oz. grated parmesan cheese
  1. In a large skillet over high, fry the squash and portobello mushrooms in olive oil. Fry each in a single layer, using as many batches as needed. Flip and cook both sides until well browned. Remove to paper towels and season with salt.
  2. Season the ricotta along with nutmeg, salt and pepper to taste, then beat in the eggs.
  3. Saute the onion & garlic in a good amount of olive oil, add the tomato sauce and lemon zest, simmer 5 minutes. Add salt to taste.
  4. Oil an 11" x 13" pan (at least 2" deep). Build up layers of noodles, sauce, squash and mushrooms, ricotta mixture, and mozzarella. Be sure to get the noodles quite wet if they are the no-boil type and need plenty of moisture. You'll have about 4 layers total. I do sauce on every layer, but ricotta on some and mozzarella on others. Do what you feel.
  5. Finish with a heavy layer of mozzarella and the parm, mixed together.
  6. Bake at 375 F., covering with tin foil part of the time if needed to avoid overbrowning. It is done when internal temp is say 170 F. (check a few spots) or when you can easily pierce the noodles with a fork, and the sauce is bubbling around the sides. Don't overcook and let the noodles get soggy.
  7. If the cheese isn't crispy and brown enough, finish judiciously with the broiler.
  8. Allow to rest at least 15 minutes before serving so it has time to set up a bit.

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Posted by Michael Natkin on Monday, September 21st, 2009 in Favorites, Kid Friendly, Main Courses, Recipes.

27 Responses to “Summer Squash and Portobello Mushroom Vegetarian Lasagna – Recipe”

  1. Reply
    September 21, 2009 at 10:38 am #

    what a lovely laaga recipe, i really like it because i love vegeable,s but that’s not all, my husband is a vegetarian, and he will love this fr sure,

    thanks from london.,


  2. Reply
    September 21, 2009 at 6:25 pm #

    I’ve just gotten back on the make my own pasta wagon – I can feel a veggie lasagne coming on with homemade lasagna sheets! Looks like a great recipe – I might mix and match it a bit with the original spinach recipe, it’s just the end of winter here and I’ve still got a lot of spinach and silver beet to get through!

  3. Reply
    September 22, 2009 at 2:02 am #

    I’m such a lasagne fan – herbivore or cariavore, it’s all delicious to me! I am going to have to give this one a go for sure! Thanks for the lovely recipe 🙂

  4. Reply
    September 22, 2009 at 5:48 am #

    This is fabulous! i have wanted to try a lasagna for a long time now..
    portabellas do tend to overpower everything sometimes..

  5. Reply
    September 22, 2009 at 10:01 pm #

    Very cool recipe, just what I’ve been looking for… yummy lasagna!

  6. Reply
    September 26, 2009 at 2:42 pm #

    Michael, this looks and sounds positively divine. I can’t wait to try it! Thanks

  7. Reply
    February 1, 2010 at 11:23 am #

    I like to make smaller portions for myself to have a couple of servings, so I made this is my Lodge cast iron skillet, and it was delicious!!!

    See more uses for cast iron at my blog


  8. Reply
    April 23, 2010 at 10:34 am #

    I made this recipe and it is truly awesome! I am going to make it again this weekend. The best vegetarian lasagne I have ever had.

  9. Reply
    May 17, 2010 at 10:35 pm #

    I’m definitely making this this week! Thanks for sharing the recipe!

  10. Reply
    July 4, 2010 at 7:50 pm #

    yum! This is in the oven right now and I’m so excited!

    Since ricotta is always overpriced (or at least it is where I shop) and I figured the zucchini and mushrooms would take a while to cooked, I made my own ricotta while the veggies were frying. It’s incredibly easy and surprisingly quick!

    If anybody’s interested…
    1 gallon milk + 4 cups buttermilk
    combine in pot, heat over med-high
    wait a few minutes, scoop out curds, put curds in fine mesh strainer, and you have ricotta!!!

  11. Reply
    Michael Natkin
    July 6, 2010 at 3:22 pm #

    I like the idea of making it with homemade ricotta. How did it turn out?

  12. Reply
    July 6, 2010 at 5:24 pm #

    Delicious!! It got a bit lumpier when I cooked it, but I didn’t mind at all. I made it while cooking the zucchini, so it didn’t add any cook time to the recipe. I made my first batch of ricotta a few months ago and it’s honestly the best and easiest thing in the world. Plus, you feel really hardcore making cheese!

  13. Reply
    April 28, 2011 at 2:28 pm #

    I added some marinated artichokes to the recipe and it was delicious!

  14. Reply
    April 28, 2011 at 2:30 pm #

    “I also did not have ricotta first time and substituted cream cheese – it was heavenly though maybe not so much on the calories!!

  15. Reply
    April 29, 2011 at 10:08 am #

    OMG!! IM GOING TO MAKE THIS!!! I put your link on my blog:))link to

  16. Reply
    J P
    August 13, 2011 at 1:16 pm #

    just made it. delicious! (tho i would probably skip the lemon zest next time)

  17. Reply
    July 11, 2012 at 6:25 pm #

    Can you explain what cutting on the bias means?

    I plan to try the recipe, but we are vegan, so I’ll have to experiment. I’m thinking that mochi can replace the ricotta, and I’ll just leave the eggs out.

    • Reply
      July 11, 2012 at 9:51 pm #

      “On the bias” means diagonally, but in this case it specifically means with your knife tilted an angle to the cutting board.

  18. Reply
    December 15, 2012 at 3:11 pm #

    I am new to this site & wanted to make the Summer Squash & Portobello Lasagna and noticed that you used Parmesan cheese. Maybe you should recommend vegan Parmesan since regular Parmesan is made with rennet. Rennet, for the unenlightened, is a nice way of saying “enzymes from animals’ stomachs.” And guess how they get those enzymes out?

    • Reply
      December 15, 2012 at 10:35 pm #

      Hey Rita –

      The situation is actually a little more complicated than that. You are quite right that Parmigiano Reggiano is made with animal rennet, because it is a DOP product so the formula is never changed; this is true of many European cheeses. Many other cheeses, especially higher volume ones, are made using microbial or vegetable rennet these days because it is less expensive. It can be challenging to find out exactly what is used in what cheese though. Stores with knowledgeable cheesemongers may know. I bought a very nice aged cow’s milk cheese that was similar in style to Parmigiano Reggiano at Whole Foods last week, but unfortunately I can’t think of the name of it to pass on right now. I’ll try and remember to add it here next time I see it.

      – Michael

    • Reply
      December 24, 2012 at 10:54 am #

      I remember the brand of Parmesan-type cheese with non-animal rennet that I like. Sarvecchio: link to . Very respectable flavor and texture.

      • Reply
        December 27, 2012 at 9:24 pm #

        Thank you very much for this. I will look for that cheese Michael.

  19. Reply
    August 6, 2013 at 2:01 pm #

    I started making this dish tonight, and I find it very difficult to believe that the prep time on this can possibly be 30 minutes. You have the same prep time for both this and the spinach and ricotta lasagna, even though this one requires frying six squash + six large portobellos until well browned. The frying alone — in a large skillet, without crowding the pan — has taken me so long that I have just put two frozen pizzas in the oven for tonight’s dinner because the lasagna will not be done in time. I’m sure the lasagna will be delicious, but I won’t find out tonight. Sigh.

    • Reply
      August 6, 2013 at 2:14 pm #

      Hey Sheela – I’m sorry this didn’t work out well for you, at least today. That prep time seems about right to me; possibly your skillet might not be hot enough? It should just be 2 or 3 minutes per side to brown the vegetables, and maybe two batches each of squash and mushrooms. But of course prep times are just approximations, they will always vary per person. I hope you are able to finish cooking it tomorrow!

  20. Reply
    August 8, 2013 at 6:54 am #

    Hi Michael, thanks, I did finish making the dish last night, and it turned out well. One thought: I appreciated the photo showing how well-browned the squash should be, but it might have been even more useful if that photo had shown them in the pan. I only did about 5-6 zucchini slices per batch in my pan because any more than that would have felt crowded, but that meant that I did almost ten batches altogether. It took over an hour! You must have either had more slices per batch or a much bigger pan. I also would have liked to see a general guideline in terms of baking time, if only to help me plan ahead. I think your recipes might be a bit advanced for me, but I guess that gives me something to work toward! Thanks again.

  21. Reply
    August 9, 2013 at 7:22 pm #

    Hey Sheela – I’m really glad it ultimately came out well! For sure, more “action” shots would be a good thing to make it easier to cook from the recipes. I’m also thinking that maybe 1/8″ isn’t an accurate measurement I’ve given, because now that I think about it, that would mean you’d end up with an awful lot of slices. Thank you for the feedback!

  22. Reply
    January 22, 2014 at 3:40 am #

    wow i am a lacto vegetarian i only eat rice,noodles, pasta with soup that shows i’m not eating healthy so i just thought of trying things check websites that i have neva done before and get ideas from others wow there is a lot of things to cook out there and have a balanced meal even though i don’t know some veggies you mention i will look them up find pics go to fruit and veg buy them and try them, out with the boring diet i need to live more eat more my mom will scream if she sees the way i am now regret neva helping with cooking

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