Heat the butter and flour in a saucepan over medium high heat, whisking together for 2-3 minutes to cook out the raw flour taste. Slowly add the milk, whisking continuously, until the milks is fully incorporated and the sauce has thickened. Stir in the salt, pepper, and Parmesan and set aside.
Heat the oil in a large skillet over medium high heat, then add the carrot, onion, and pepper, and cook until slightly softened, about 5 minutes. Add the chicken and half of the béchamel sauce, then stir in the tomatoes and basil.
Pour ½ cup of the sauce into the bottom of an 8x8-inch glass baking dish and lay 1 egg roll wrapper on top. Layer ¼ of the chicken mixture over the egg roll wrapper, then half of the cottage cheese. Place another wrapper over the mixture and press down gently, then layer another ¼ of the chicken mixture on top, and half of the mozzarella over the chicken. Repeat for 2 more layers: egg roll wrapper, chicken mixture, cottage cheese, egg roll wrapper, chicken mixture, mozzarella cheese. End with a final egg roll wrapper and then pour the remaining ½ cup of béchamel sauce over the top and smooth to the edges. Sprinkle with pepper and bake uncovered at 375 degrees until bubbly and hot, about 30-45 minutes.
Recipe by Cooking With Michele® at https://cookingwithmichele.com/2014/12/chicken-lasagna-bechamel-sauce/