Prep Time: 25 mins | Cook Time: 1 hour | Total Time: 1 hour 25 mins
2 1/2 Tbsp. olive oil
1 cup chopped onion
2 Tbsp. minced garlic
8 oz. white mushrooms, thinly sliced
1 tsp. dried basil
1 tsp. dried oregano
1/2 tsp. red pepper flakes
1 1/2 tsp. kosher salt, divided
1 (6 oz.) bag fresh baby spinach
2 cups shredded cooked chicken
2 1/2 cups low-sodium chicken stock
1 1/2 cups milk (I used whole milk)
1/4 tsp. nutmeg
1/4 cup all-purpose flour
1/2 cup shredded Parmesan cheese
8 no-boil lasagna noodles
1 1/4 cups shredded mozzarella cheese
Preheat the oven to 375 degrees F.
Heat a large sauté pan over medium-high heat. When hot, add oil and then the onions, garlic, mushrooms, basil, oregano, red pepper flakes, and 1/2 teaspoon of salt. Sauté for 5 minutes or until the mushrooms soften while stirring occasionally. Make sure all of the liquid has evaporated from the mushrooms before going to step 3.
Stir in spinach and cook until the spinach wilts. Then remove the pan from the heat and stir in the cooked chicken.
In a small saucepan, combine the chicken broth, milk, nutmeg, and remaining 1 teaspoon of salt. Bring to a slow simmer over medium heat. Once the mixture starts to bubble up around the edges, gradually whisk in the flour and let simmer until thickened, about 5-10 minutes. Stir in Parmesan cheese and then remove from heat.
Pour 1/2 cup sauce into bottom of 10X10 square baking dish, top with 2 noodles, 1 cup chicken mixture, 1 cup sauce, and 1/4 cup mozzarella, making sure noodles are covered with sauce. You can even press them down lightly. Repeat 3 more layers with noodles, chicken, sauce, and cheese. Last layer will have slightly more sauce and remaining cheese on top.
Cover baking dish with aluminum foil and bake for 25 minutes. Uncover and bake for 15 minutes longer. If desired, broil for 2-3 minutes for golden brown top. Let stand 5-8 minutes before serving.