Preparation Steps

• 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.
• 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.
• Add flour to saucepan and stir to combine. Let cook for 30 seconds or so.
• Add 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. Cook, stirring occasionally, for an additional 8-10 minutes until sauce has thickened to your desired consistency.
• Turn off the heat, then add spinach and ⅔ of the parmesan cheese to the sauce. Stir until spinach has wilted and cheese has melted into the sauce.
• Taste the sauce and adjust seasoning with extra salt or pepper as needed.
• Heat oven to 375 degrees F if baking immediately.
• Spread a thin layer of sauce over the bottom of a baking dish. Layer lasagna noodles, sauce, and mozzarella cheese until you run out of ingredients. Top with remaining mozzarella and parmesan.
• Bake lasagna for 30-40 minutes until cheese has melted and edges are lightly browned.
• Let lasagna cool for 10 minutes before serving. Top with fresh parsley, cut, and enjoy.