INGREDIENTS
- 1/2 lb. lasagna noodles (dried or ready-to-bake – see recipe notes!)
- 3 Tbsp. extra virgin olive oil (you could use butter or ghee if you prefer)
- 1/2 large yellow onion, diced
- 4 cloves garlic, minced
- 1 lb. baby portobello mushrooms, sliced
- Kosher salt and pepper to taste
- 1/4 cup flour
- 1.75 cups vegetable stock (you could also use chicken or turkey stock)
- 1/2 cup heavy cream
- 4 cups fresh spinach
- 1.5 cups shredded parmesan cheese, divided
- 8 oz. fresh mozzarella cheese, thinly sliced or shredded
- 1/4 cup chopped parsley for garnish (optional)
INSTRUCTIONS
GET THE NOODLES READY.
- If you’re using dried lasagna noodles, cook them according to package directions in very salty water until 5 minutes less than al dente. Drain and set aside. I recommend laying the noodles out in a single layer on a lightly oiled baking sheet as soon as they’re cooked – it keeps them from sticking together so they’re easier to work with later! (If you’re using ready-to-bake noodles, you can skip this step – see recipe notes).
MAKE THE SAUCE.
- Heat a large saucepan over medium-high heat. When pan is hot, drizzle in the olive oil.
- Add onion and garlic to pan and stir to combine. Cook 1-2 minutes until onion has begun to soften.
- Add sliced mushrooms to pan and cook, stirring occasionally, for 4-5 minutes until onion is translucent and mushrooms have reduced in size.
- Add salt and pepper to taste and stir to combine (don’t skimp on the seasonings here – salt is what brings out the flavor! I usually add up to 1 tsp. of kosher salt at this step).
- Add flour to saucepan and stir to combine. Let cook for 30 seconds or so to ensure the flour cooks through.
- Add the vegetable stock to the pan a little at a time, stirring as you go to break up any lumps of flour. Bring mixture to a simmer and cook, stirring occasionally, for 8-10 minutes until sauce has begun to thicken.
- Add heavy cream to sauce and stir to combine. Return sauce to a simmer and cook, stirring occasionally, for an additional 8-10 minutes until sauce has thickened to your desired consistency. (The sauce shouldn’t be watery, but it doesn’t need to be quite as thick as, say, a bechamel or a cheese sauce: it will thicken when cheese is added and as it cools, and the lasagna noodles will absorb some of the moisture as it cooks. Watch the how-to video above to see an example!)
- Turn off the heat, then add spinach and 2/3 of the parmesan cheese to the sauce (save the last cup of parmesan cheese for topping the lasagna!). Stir until spinach has wilted and cheese has melted into the sauce.
- Taste the sauce! Grab a spoon and steal a bite – then add extra kosher salt or pepper as needed. (I almost always add another 1/2 teaspoon or so of Kosher salt during this step).
ASSEMBLE THE LASAGNA.
- Heat oven to 375 degrees F (if you plan to bake your lasagna immediately – if you’re freezing it for later, you can skip this step).
- Spread a thin layer of sauce over the bottom of a medium-sized baking dish (I use an 8×10″ dish – see recipe notes). Put down a layer of lasagna noodles, followed by a few ladlefuls of sauce, followed by a few slices of mozzarella cheese. Repeat until you run out of noodles and sauce. Top the final layer with any remaining mozzarella cheese and the rest of your parmesan.
- Bake lasagna for 30-40 minutes until cheese has melted and the edges are lightly browned. (If you’re freezing the lasagna or making it ahead of time, skip this step and see recipe notes).
- Let lasagna cool for 10 minutes before serving. Top with fresh parsley, cut, and enjoy.
NOTES
This post was originally published in 2012. The recipe instructions and ingredients were updated for clarity and quality based on reader feedback and additional testing in 2018.
This is a great base recipe – make it as-is or add some extra things to make it a little heartier! Shredded chicken, leftover Thanksgiving turkey, and sausage are all great protein options. You can also add any veggies you have on hand: I like bell peppers, broccoli, carrots, tomatoes, asparagus, or brussels sprouts in this recipe.
To use ready-to-cook lasagna noodles, I recommend adding an extra 1/4 cup or so of vegetable stock to your sauce – ready-to-cook noodles soak up more liquid, so an extra splash of liquid helps them stay moist! I’ve had good luck making this recipe with ready-to-cook noodles and you can absolutely make that swap if you like.
To make this lasagna ahead of time, you have a few different options. The assembled lasagna freezes well, but the sauce also freezes well on its own. To freeze or refrigerate an assembled lasagna, let it cool completely and wrap tightly with plastic wrap. Lasagna can go straight from the fridge or freezer into a COLD oven (let the oven heat up slowly with the cold dish already inside to prevent any ceramic or glass dishes from breaking) and bake for 1-2 hours until cheese has melted and lasagna has cooked through (refrigerated lasagna will generally only take an hour when you start it in a cold oven; frozen lasagna will take a bit longer).
I usually use an 8×10 casserole dish for this lasagna, which typically holds 3-4 layers of noodles and sauce. You could use a 9×13 dish if you like (you may just need fewer layers – but you can always stack a few slices of lasagna on top of each other for that sky-high look!) or use a smaller baking dish for more layers and taller lasagna.
Use 2 cups frozen spinach in place of fresh spinach if you like.
Use a high-quality parmesan 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. Strict vegetarians can opt for a vegetarian parmesan cheese made without rennet.
PS – If you loved the way this recipe was originally written, no worries! Shoot us an email and we’re happy to send an original copy your way (although we think you’ll agree that this improved version is even better!)
