Creamy Spinach & Mushroom Layered Delight: A Hearty, Savory Comfort Dish

Make the roux: In a medium saucepan, melt the butter over medium heat. Add the flour and cook, whisking constantly for about 1-2 minutes, until it forms a smooth paste.
Add the milk and cream: Gradually whisk in the milk and heavy cream, ensuring the mixture remains smooth. Bring it to a simmer while continuing to whisk until the sauce thickens, about 5-7 minutes.
Season the sauce: Stir in the garlic powder, onion powder, nutmeg (if using), salt, and pepper. Remove the sauce from heat and fold in the grated Parmesan cheese. Set aside.
Step 2: Prepare the vegetables
Sauté the mushrooms and onions: Heat olive oil in a large skillet over medium heat. Add the chopped onion and cook until softened, about 4 minutes. Add the sliced mushrooms and cook, stirring occasionally, until the mushrooms release their moisture and become golden brown, about 8-10 minutes.
Wilt the spinach: Add the garlic and cook for 30 seconds until fragrant. Add the spinach to the skillet in batches, letting each batch wilt down before adding more. Cook until the spinach is fully wilted and the mixture is well combined. Remove from heat.
Step 3: Assemble the layered delight
Layer the dish: Preheat your oven to 375°F (190°C). In a greased baking dish (9×9-inch or similar size), spread half of the vegetable mixture evenly at the bottom. Pour half of the creamy sauce over the top. Repeat with the remaining vegetables and sauce, creating two layers.
Top with cheese: Sprinkle the shredded mozzarella and grated Parmesan evenly over the top of the final layer.
Step 4: Bake and serve
Bake the dish: Place the baking dish in the oven and bake for 20-25 minutes, or until the cheese is melted, bubbly, and golden brown on top.
Serve: Let the dish cool for a few minutes before serving. Slice into squares and serve hot.
Serving and Storage Tips