Preheat oven 350 degrees

Cook the mushrooms and onion mixture:

• In a saute pan, heat olive oil over medium heat.
• Add mushrooms, onions, half of the thyme, half of the garlic, salt, and black pepper.
• Mix to combine. Cook 8 to 10 minutes until the mushroom liquid has evaporated.
• Turn off the heat and set aside.

Make the Béchamel Sauce: (I usually do this step while the mushrooms are cooking)

• In a 4 or 5 quart dutch oven, melt the butter over medium to medium low heat.

  Note: I like to slightly brown the butter. The butter can burn easily if the heat is too high.
• Slowly whisk in the flour. Cook 1 to 2 minutes.

  Note: Be careful not to burn the Roux (this is simply the butter and flour mixture).
• Slowly add the milk and heavy cream, whisking consistently.
• Bring to a boil. Cook 3 to 5 minutes until sauce starts to thicken.
• Add in 1 cup of the shredded mozzarella cheese, the remaining thyme, garlic and the nutmeg. Whisk until the cheese melts completely.
• Continue cooking for 3 to 5 minutes over medium to medium low heat. Whisk frequently
• Add the spinach. Stir until fully incorporated with the sauce.
• Add the mushroom mixture. Stir until fully incorporated.
• Turn off the heat.

Assemble the Lasagna:

• Butter an 8-inch rectangular baking dish or pan with at least a 2-inch height. Place on a sheet pan.
• Spread 1/2 cup of the vegetables béchamel sauce on the bottom of the dish.
• Add 2 lasagna sheets over the sauce.

  Note: Depending on your bowl, you can use up to 3 sheets of lasagna per layer. Do not overlap the sheets as they will expand during the baking process.

  You can use regular lasagna sheets if you prefer - you know, the old fashion ones that needs to be pre-cooked.
• Spread 1/2 cup sauce to cover the noodles.
• Sprinkle 1/3 of the remaining shredded mozzarella cheese.
• Sprinkle 1/3 cup of the parmigiano reggiano cheese.
• Sprinkle 1/3 cup of the mozzarella chunks.
• Add 2 sheets of lasagna over the cheese.
• Continue the layering process of sauce, shredded mozzarella, parmigiano reggiano cheese and chunks of mozzarella cheese.

  Note: You should have 3 layers of lasagna sheets.
• Drizzle with olive oil.
• Bake at 350 degrees for 30 to 35 minutes until nice and bubbly and cheese is lightly brown.
• Remove the lasagna from the oven and allow to rest for 20 to 30 minutes before cutting.

  Note: The aroma from this delicious tasting lasagna will surely cause you to cut and eat it before the cooling process. And that is quite okay!
• Serve it up as a side dish or a meal. Enjoy!