While chicken mixture is cooking, cook lasagna noodles according to package directions and drain.
Drizzle oil into a 3-quart Dutch oven over medium heat. Add chicken, onion, and celery and cook until meat is no longer pink and vegetables are fork tender, about 10 minutes. Add garlic and cook for another minute or so until fragrant. Then stir in tomatoes, ¾ cup of buffalo sauce, water, salt and pepper. Bring to a boil and reduce the heat to simmer and allow to cook about 5 more minutes.
Preheat oven to 350º F. Spray 9x13 baking dish with nonstick cooking spray and set aside.