Tuna Noodle Casserole

8 ounces whole-wheat egg noodles
2 tablespoons olive oil
1/2 cup chopped onion
1/2 cup chopped carrot
1/2 cup chopped celery
2 tablespoons all-purpose flour
2 3/4 cup nonfat milk
1/3 cup reduced-fat cream cheese
2 tablespoons Dijon mustard
Dash salt
Dash black pepper
1/2 cup grated Parmigiano-Reggiano cheese
2 5-ounce cans tuna, drained
Whole wheat bread crumbs

Cook noodles according to package, omitting salt and fat. Drain, set aside. Heat a large skillet over medium heat. Add oil to pan. Add onion, carrot and celery, cooking until tender, about 6 minutes. Sprinkle with flour, cook one minute, stirring constantly. Gradually stir in milk, stirring constantly with a whisk until slightly thick. Stir in cream cheese, mustard, salt and pepper. Cook about 2 minutes. Remove pan from heat. Stir in noodles, 1/4 cup of the Parmigiano-Reggiano cheese and tuna. Spoon mixture into 2-quart baking dish, coated with nonstick cooking spray. Sprinkle with whole wheat bread crumbs and remaining 1/4 cup of Parmigiano-Reggiano. Bake at 350 for about 10 minutes, then finish off under a low broiler. Let sit 5 minutes before serving.