Chicken Lasagna with Spinach

Heat 3 tablespoons butter and olive oil in a large skillet over medium heat. Add chicken, mushrooms, onion, 1/2 of the minced garlic, 1/4 teaspoon salt, and 1/4 teaspoon pepper; cook until chicken is no longer pink in the center and the juices run clear, about 10 minutes. Remove from the heat and stir in spinach; set aside.

While chicken is cooking, bring 2 large pots of lightly salted water to a boil. Cook lasagna noodles in the boiling water in one pot, stirring occasionally, until tender yet firm to the bite, about 8 minutes. Drain and set aside. Drop spinach into the boiling water in the second pot and blanch for 1 minute; pour into a colander to drain.

Combine cream, half-and-half, remaining garlic, onion powder, sage, and bay leaf in a microwave-safe bowl. Microwave on high power in 1-minute increments until boiling; stir well.

Preheat the oven to 350 degrees F (175 degrees C). Spray a 12x15-inch piece of aluminum foil with cooking spray.

Melt remaining 5 tablespoons butter in a medium saucepan over medium-high heat. Add flour; stir and cook until golden brown, 2 to 3 minutes. Continue stirring and add cream mixture. Cook until thickened, about 3 minutes. Stir in 1 1/2 cups Parmesan cheese, remaining 1/2 teaspoon each salt and pepper, and nutmeg. Remove from heat.

Meanwhile, mix ricotta cheese and 3 cups mozzarella cheese in a medium bowl. Fold in 1/4 cup of the cream sauce.

Assemble lasagna in a deep 9x13-inch baking dish as follows, spreading ingredients in each layer: 1/2 cup cream sauce, 1/3 of the chicken-spinach mixture, 1/3 of the noodles, 1/2 cup cream sauce, 1/3 of the chicken-spinach mixture, 1/2 of the ricotta mixture, 1/4 cup cream sauce, 1/3 of the noodles, 1/2 cup cream sauce, remaining chicken-spinach mixture, remaining ricotta mixture, remaining noodles, remaining cream sauce, remaining Parmesan, and remaining mozzarella. Cover with the aluminum foil, sprayed-side down.

Bake in the preheated oven for 30 minutes. Remove foil and bake until top starts to turn golden, about 15 minutes more. Remove from oven and let rest for 10 minutes before serving.