Spinach Lasagna with Portobellos and Béchamel

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Spinach lasagna with a velvety béchamel sauce and a deeply flavored filling makes the best cozy comfort food for fall and winter.

Spinach Lasagna with Portobellos and Bechamel Sauce 780 | Umami Girl


Frozen spinach works great in this recipe. Just be sure to squeeze out as much moisture as you can before adding it to the filling.

Why I apparently really needed this spinach lasagna in 2009

Oh, what a long, cold winter it’s been, friends. The hopeful among us who’d been looking to March as a white knight have now been unequivocally informed that there will be more white and less knight, at least for the present. Well, March, I’ve never much liked you anyway, at least until the 17th; and this year, you’ll need to haul out the really good beer to make amends for this dastardly start of yours. Fourteen degrees, is that what you’ve got? There had better be a complimentary Irish castle tour for two at the end of this story. Bring it, beeotch. I’m already packed.

Spinach Lasagna with Portobellos and Bechamel Sauce 780 | Umami Girl

(Also? This spinach lasagna post…

…was originally named, “While the gettin’s good: How this ectomorph gained 5 pounds in 4 weeks.” That was the URL, too. Websites were…different…in 2009. Okay, back to the odd task at hand.)

But umami girl, you ask thoughtfully, won’t you need those clothes in the next couple of weeks? Thanks for looking out for me, buddy; but frankly, they were getting a little snug anyway, what with all the not leaving of the house and the eating of copious quantities of comfort foods. (Great news, though – gorging on comfort now makes a girl trendy.) Speaking of which, have I got a gorgeous lasagna for you. Packed with the goodness of spinach and portobellos, it uses both pillowy ricotta and a luscious béchamel sauce to fortify us against these last, cruel days of winter. As a bonus, it’s so on-trend right now that I think I saw someone wearing it as a tote on the Lower East Side yesterday. Brains, beauty and brawn. What more could you need?

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Spinach Lasagna with Portobellos and Béchamel

Packed with the goodness of spinach and portobellos, this spinach lasagna uses both pillowy ricotta and a luscious béchamel sauce to fortify us against whatever comes our way.

Prep Time 15 minutes
Cook Time 1 hour
Additional Time 10 minutes
Total Time 1 hour 25 minutes
Serves 12


  • 6 tablespoons butter, divided
  • 6 large portobello mushrooms
  • 1 large yellow onion, finely diced
  • 6 cloves garlic, chopped
  • 20 ounces frozen spinach (not chopped is preferable, but chopped is fine)
  • 2 large eggs
  • 32 ounces whole-milk ricotta cheese
  • 2 cups Parmigiano-Reggiano cheese, divided
  • ¼ teaspoon nutmeg, divided
  • 4 tablespoons all-purpose flour
  • 5 cups whole milk
  • 9 ounces no-boil lasagna noodles
  • Fine sea salt and freshly ground black pepper
  • Marinara sauce for serving, optional


  1. Preheat oven to 425°F with a rack in the center.

For the Filling

  1. Finely chop the portobellos (into about ¼-inch dice), or roughly chop them with a knife and then pulse briefly in a food processor to achieve the same result.
  2. Melt 2 tablespoons of the butter in a large non-stick skillet over medium-high heat.
  3. Add the portobellos and sauté until very fragrant and beginning to brown.
  4. Add the onion and garlic, along with a good pinch of salt, and reduce the heat to medium. Sauté, stirring occasionally, until the onions and garlic have softened a bit but not browned.
  5. Meanwhile, cook the spinach according to package directions, but just to the point that it is warm. Drain and let it sit until it is cool enough to handle, and then pick it up by the handful and squeeze out as much liquid as you can.
  6. Crack the eggs into a large bowl and beat lightly. Add the ricotta, 3/4 cup Parmigiano cheese, the portobello mixture, the drained spinach, 1/8 teaspoon nutmeg, and a generous amount of salt and pepper. Mix thoroughly.

For the Béchamel Sauce

  1. Melt the remaining 4 tablespoons butter in a medium, heavy-bottomed pot over medium heat.
  2. Add the flour all at once and cook, stirring constantly, for one minute.
  3. Add the milk, raise the heat to high, and bring to a boil, stirring almost constantly.
  4. When the mixture boils, reduce the heat so it is simmering vigorously and cook for ten minutes or so, stirring occasionally, until the sauce is thick enough to coat the back of your spoon.
  5. Turn off the heat and add 3/4 cup Parmigiano cheese, remaining 1/8 teaspoon nutmeg, and salt and pepper to taste.

To Assemble and Bake the Lasagna

  1. Lightly oil a deep 9×13-inch baking pan.
  2. Spread a thin layer of the béchamel to coat the bottom of the pan.
  3. Layer 1/3 of the lasagna noodles over the sauce. Top the noodles with half of the ricotta filling mixture.
  4. Repeat with another layer of béchamel, noodles and ricotta filling.
  5. For the last layer, put the remaining 1/3 of the noodles directly over the second layer of ricotta filling, pour the remaining béchamel on top, and sprinkle with the remaining 1/2 cup of Parmigiano cheese and some more freshly ground black pepper.
  6. Cover the pan with foil and bake for 30 minutes.
  7. Remove foil and bake for an additional 10 minutes to brown the top.
  8. Rest lasagna for 10 minutes or so before serving with marinara sauce to pass at the table if you like.

Nutrition Information

Amount Per Serving:

Calories:: 428 Total Fat:: 23.7g Carbohydrates:: 30.8g Fiber:: 3.8g Protein:: 22.9g

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  1. Karin

    How many servings does it makes?

  2. Katherine

    I made this last night for a holiday party because I knew we had some vegetarians coming….EVERYONE LOVED it!!! It was so delicious!!! I did, however, have a lot of leftover bechamel sauce but my pan was smaller than 9×12. Anyways…DELICIOUS thank you!

    1. So happy to hear that — thanks for letting me know!

  3. Danielle

    I forgot to tell you when we bumped into each other on Monday that the girls and I enjoyed Jill’s pancakes last weekend that she made thanks to your great recipe. I am psyched that there is a great tasting pancake recipe out there from scratch!

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  5. Layla, I just did an inadvertent little happy dance when I read that. Yay!

  6. Layla

    Carolyn, I made your recipe for friends on Saturday (although it was a balmy 65 degrees (70?) here in Washington) and it was fantastic. Thank you! Send love to the kiddos for me.

  7. Danielle

    Carolyn, have already given that idea serious thought…..just can’t get my hands on any(KIDDING!) :). Hope you are well.

  8. Danielle, just so you know, a little Xanax ground up with a mortar and pestle and sprinkled on top makes a delicious addition to this, or really any, recipe. (Alright, I know – kidding, kidding.) Sorry you’re feeling unsettled!

  9. Danielle

    As I am sick as a dog on this very gray, but warmer, March day…I found myself feeling guilty for not cooking in the last day or two so I decided to come here! And, to my surprise was just the recipe I was thinking about. That fabulous lasagna you made for us on that very enjoyable Sunday :)!!!! B/T browsing your’s and Julie’s sites my guilt gets the best of me when I haven’t cooked like I love to do in awhile. Even though I have good reason…80% of my kitchen is boxed up and at our house in Chatham. HMMM…when will life get back to normal???? Thank you for keeping me inspired in these very dark days. How is that for drama :)!!

  10. Jill, Edie, you’re the best. And sorry, right, so is March 1. Along those lines, a little shout-out to March 6, too, for Edie. Big month, big month! What was I complaining about?

    Jill, I was just thinking on the 1st how different your birthdays must have been in CA. I got nothin for ya, I’m afraid, other than what umami boy says to me once in a while: “You married it.” Or in this case, sweets, “You moved to it.”

    Edie, any secrets from your own spinach lasagna making? There are so many good variations.

  11. Made a spinach lasagna today but not this one. Look forward to trying this recipe. It sounds delicious. What I expect from the super taster!

  12. Jill

    hey girlie!! LOVE your post as usual… but this time especially since I know first hand how DELICIOUS this yummy lasagna is… now the question shall be… will I ever actually make it or just wait patiently & hopefully for you to make it again! Bwahaha! 😉

    Oh and what do you mean the only good day in Mar is the 17th?! My dear, you forgot about the very important FIRST day of the month! Although with the sucky weather and all…this California girl is calling for a DO OVER! What happened to the good ‘ol days of bbq’s outside for my bday?! Humph… oh yeah, I live in NJ now! Oh well.