Instructions

  1. Preheat oven to 375°F.
  2. Cook noodles, drain, and set aside.
  3. Meanwhile, combine breadcrumbs with 1 tablespoon melted butter.
  4. Set aside.
  5. For sauce, in a medium saucepan cook onion and celery in 1/4 cup butter until softened.
  6. Stir in flour, salt, mustard powder, and black pepper.
  7. Add milk all at once.
  8. Whisk until slightly thickened and bubbly.
  9. Combine sauce, tuna, cheese, roasted pepper or pimiento, and cooked noodles.
  10. Transfer to a 1 1/2 quart casserole dish.
  11. Sprinkle with breadcrumb mixture.
  12. Bake, uncovered, for 20-25 minutes until bubbly and breadcrumbs are golden brown.