01 - Preheat the oven to 375°F. Grease a 9x13-inch baking dish with butter or nonstick spray.
02 - Bring a large pot of salted water to a boil. Cook the lasagna noodles according to package directions until al dente. Drain carefully and lay them flat on a baking sheet or clean kitchen towel to prevent sticking.
03 - In a large mixing bowl, combine the shredded chicken, ricotta cheese, 1 cup mozzarella, 3/4 cup Parmesan, minced garlic, chopped parsley, salt, and black pepper. Stir until all ingredients are evenly incorporated.
04 - Melt the butter in a medium saucepan over medium heat. Add the minced garlic and sauté for 1 minute until fragrant. Sprinkle in the flour and whisk constantly for 1 minute to form a roux. Gradually pour in the whole milk while whisking to prevent lumps. Simmer for 3 to 4 minutes, stirring frequently, until the sauce thickens enough to coat the back of a spoon. Remove from heat and stir in 1/3 cup Parmesan cheese, salt, and pepper.
05 - Spread 1/2 cup of the béchamel sauce evenly across the bottom of the prepared baking dish. Lay each cooked noodle flat and spread approximately 2 to 3 tablespoons of the chicken filling over the surface. Roll each noodle up tightly and place seam side down in the dish, arranging them in a single layer.
06 - Pour the remaining béchamel sauce over the assembled roll ups, coating them evenly. Sprinkle the 2 cups of mozzarella and 1/2 cup of Parmesan over the top.
07 - Cover the dish tightly with aluminum foil and bake for 25 minutes. Remove the foil and continue baking for 10 to 15 minutes until the cheese is melted, golden, and bubbling.
08 - Remove from the oven and let rest for 5 minutes before serving. Garnish with additional chopped fresh parsley if desired.