Preheat oven to 325 degrees F (165 degrees C). Bring a large pot of lightly salted water to a boil. Add pasta, and cook for 8 to 10 minutes, or until al dente; drain.
In a large skillet over medium-high heat, combine sausage, chicken, Cajun seasoning and sage. Cook until chicken is no longer pink and juices run clear, about 8 minutes. Remove meat from skillet with a slotted spoon, and set aside. Saute onion, celery, bell pepper and garlic until tender. Remove from heat, and stir in cooked meat and one container Alfredo sauce.
Lightly grease a 9x13 inch baking dish. Cover bottom with 4 lasagna noodles. Spread with 1/2 of the meat mixture. Repeat layers, and cover with a layer of noodles. Spread remaining Alfredo sauce over top. Top with mozzarella cheese and sprinkle with Parmesan cheese.
Bake in preheated oven for 1 hour. Let stand 15 minutes before serving.
