Creating Creamy Spinach & Mushroom Lasagna involves a series of easy steps. Simply follow these instructions to achieve the best results:

1. Preheat the Oven: Preheat your oven to 375°F (190°C).
2. Cook the Noodles: In a large pot of salted boiling water, cook the lasagna noodles according to package instructions. Drain and set aside.
3. Sauté Vegetables: In a large skillet, heat olive oil over medium heat. Add garlic and sauté until fragrant. Then add mushrooms and cook until softened, about 5-7 minutes. Stir in chopped spinach and cook until wilted. Season with oregano, salt, and pepper. Set aside to cool.
4. Prepare Béchamel Sauce: In a saucepan, prepare the béchamel sauce if you aren’t using store-bought. Melt butter, whisk in flour, gradually add milk, and whisk until thickened. Season with salt and pepper.
5. Mix Cheese: In a bowl, combine ricotta cheese, half of the mozzarella cheese, and half of the Parmesan cheese. Mix well.
6. Assemble the Lasagna: In a 9×13 inch baking dish, spoon a layer of béchamel sauce at the bottom. Place three lasagna noodles over the sauce. Spread half of the cheese mixture over the noodles, followed by half of the sautéed vegetables. Repeat the layers, ending with a layer of noodles topped with béchamel sauce and a generous sprinkle of remaining mozzarella and Parmesan cheese.
7. Cover and Bake: Cover the dish with aluminum foil and bake in the preheated oven for 30 minutes. Remove the foil and bake for an additional 15 minutes until bubbly and golden brown.
8. Cool Before Serving: Remove the lasagna from the oven and allow it to cool for 10-15 minutes before slicing.

Following these simple steps will ensure your Creamy Spinach & Mushroom Lasagna turns out perfectly delicious every time.