Preheat the oven to 350 degrees F. Grease a 9X13 baking dish and keep it ready.
Cook the lasagna noodles according to the package instructions and keep it aside on a tray for using it later.
Heat a medium skillet with a tablespoon of butter; add the mushroom and cook until the mushroom releases the moisture. Transfer the cooked mushroom to a plate.
To a dutch oven on a medium flame add the remaining butter. Once the butter is melted, sprinkle the flour and cook for a minute. Add the minced garlic and stir in the chicken broth slowly. Add the heavy cream and cook for 2-3 minutes.
Add the seasonings; black pepper, Italian seasonings and salt. Stir in the cheddar cheese and parmesan cheese and mix well until the cheese is melted and sauce is thickened. Reserve about 1 cup prepared sauce in a bowl.
Add the cooked mushrooms and rotisserie chicken back to the pot with the remaining sauce and combine everything together.
Spread 2 tbsp of reserved sauce over the baking dish, arrange a layer of cooked lasagna noodles, spread half of the chicken mixture and top with ¼ cup mozzarella cheese. Arrange the lasagna noodles again and repeat the same.
Pour the remaining sauce over and sprinkle the mozzarella cheese on top evenly.
Cover the baking dish with aluminum foil and bake for 20 minutes. Remove the foil and cook further for 20-25 minutes until the cheese is melted.
Once done garnish the lasagna with chopped parsley and slice the lasagna to equal squares and serve.