Mushroom and Spinach Lasagna

This easy vegetarian lasagna has a light Parmesan spinach sauce and earthy mushrooms. It also freezes wonderfully – perfect for make-ahead freezer meals!


  • ½ lb. lasagna noodles
  • 3 Tbsp. extra virgin olive oil
  • ½ large yellow onion, diced
  • 2 cloves garlic, minced
  • salt and pepper to taste
  • ½ lb. baby portobello mushrooms, sliced
  • 2 Tbsp. flour
  • 2 and ⅔ cups vegetable stock
  • ¾ cup milk
  • 3 cups fresh spinach
  • 3 and ½ cups shredded Parmesan cheese, divided
  • ¼ cup chopped parsley for garnish (optional)


  1. Cook lasagna noodles according to package directions until they are 5 minutes less than al dente. The noodles should have a noticeably uncooked/crunchy center, because they will cook more in the oven.
  2. In a large saucepan, heat olive oil over medium heat. Add onion and garlic and sauté for 1-2 minutes until onion begins to soften,
  3. Add sliced mushrooms to pan and cook until onion is translucent and mushrooms have cooked down, about 5 minutes more.
  4. Add salt and pepper to taste and stir to combine.
  5. Add flour to saucepan to form a roux. Don't worry if it pulls the mushrooms and onions into big clumps - you'll break that all up when you add liquid. Cook roux for 1 minute.
  6. Add ¼ cup of the stock and stir vigorously to break up the chunks of roux in the pan. The stock will thicken noticeably. Add the rest of the stock slowly, stirring constantly, and stir to incorporate.
  7. Stir milk into sauce and bring to a simmer. Cook sauce for 10-12 minutes until it has thickened slightly.
  8. Add spinach to sauce and cook until spinach has wilted and cooked, about 5 minutes.
  9. Remove sauce from heat and add 1 and ½ cups of the Parmesan cheese to the sauce. Stir until the cheese has melted. Reserve the additional 2 cups of Parmesan for lasagna assembly.
  10. Assemble the lasagna! Spread a thin layer of the sauce on the bottom of a 9x13 baking dish to prevent sticking. Lay lasagna noodles down, then a layer of sauce, then a layer of Parmesan cheese, then repeat until pan is full and/or you run out of noodles and sauce. Make sure to end the layering with a layer of sauce topped with Parmesan cheese.
  11. When lasagna is assembled, you can either refrigerate or freeze it, or you can bake it immediately. Whenever you're ready to bake, do so at 375 degrees F for 30-35 minutes or until cheese is melted and bubbly.
  12. Garnish with fresh chopped parsley (optional) and serve immediately.


  • Add shredded chicken or turkey to this lasagna for extra protein.
  • 1% milk is listed for this recipe, but you can use whichever milk you prefer
  • Use frozen spinach in place of fresh if you like, but use just 1 cup of frozen spinach since it's already been wilted down.
  • Use REAL parmesano-reggiano cheese in this recipe if you can find it, and stay away from pre-shredded if at all possible: pre-shredded cheese is often treated with preservatives that prevent it from melting smoothly into a sauce.