Creamy Chicken Lasagna

• 6 TBSP unsalted butter, divided
• 1 lb (454g) mushrooms, sliced
• 1 onion, diced
• 4 garlic cloves, minced
• 1/2 cup (120ml) dry white wine
• 3 cups cooked and shredded or cubed chicken
• 1 16-oz (450g) package frozen spinach, defrosted and drained
• 1/2 cup plus 2 TBSP (65g) flour
• 4 cups (960ml) milk, warmed
• 1 cup (240ml) chicken stock
• 1 TBSP (15ml) Dijon mustard
• 2 tsp coarse kosher salt, or half as much if using fine salt
• 1/4 tsp freshly ground black pepper
• 16 lasagna noodles
• 1 cup (100g) Parmesan, grated
• 2 cups (200g) mozzarella cheese, grated
• 2 cups (200g) Gruyère cheese, grated
• Fresh parsley, for garnish

Instructions

1. 1

   Preheat the oven to 350°F (175°C). Grease a casserole dish lightly. Bring a large pot of salted water to a boil.

2. 2

   In a large heavy-bottomed pan, melt 2 tbsp (30g) butter over medium-high heat. Add the mushrooms and sauté for about 7 minutes until they release their liquid and become lightly golden brown. Add a pinch of salt and the onions, and continue cooking for another 5 minutes or so until the onions are softened and translucent. Add the garlic and cook for about 30 seconds, but do not let it burn or brown. Add the wine, bring it to a boil, and cook until most of the liquid has evaporated. Remove from heat, transfer to a plate, and set aside.

3. 3

   Melt the remaining 4 tbsp (57g) butter over medium heat. Add the flour and cook for a minute or two to cook off the raw taste. Pour in the warmed milk a little at a time, stirring vigorously. Add the chicken stock and continue simmering for about 10 minutes until your béchamel sauce is thickened. Season with salt and pepper, and add the mustard. Pass the sauce through a fine-mesh sieve in case there were any lumps. Stir 1/4 cup (60ml) of parmesan into the sauce. Stir the drained spinach into the sauce. Fold the chicken and mushrooms into the sauce. Adjust the seasoning.

4. 4

   Boil the noodles 1–2 minutes less than the package instructions. Drain and rinse in cold water. Mix the mozzarella, Gruyère, and the remaining 3/4 cup (180ml) of parmesan in a small bowl.

5. 5

   To assemble, spread 1/4 of the chicken mixture into the prepared baking dish. Layer 4 noodles on top, then another 1/4 of the chicken mixture and 1 cup (240ml) of cheese. Repeat the layers and ensure the top layer ends with cheese.

6. 6

   Bake uncovered for about 45 minutes until hot and bubbling. Let it cool for about 10 minutes before serving. Garnish with parsley, serve, and enjoy. Note: you can make this ahead by assembling the lasagna, covering it, and refrigerating it. If you do so, just add about 15 additional minutes to your cooking time.