Instructions

  1. Cook the egg noddles in boiling water according to package directions; drain and rinse under warm water, then set aside.
  2. Drain the tuna and flake with a fork.
  3. In a large bowl, combine tuna, cooked egg noodles, celery and onions; mix well to combine.
  4. In another small bowl, combine sour cream, mustard powder, mayo, Parmesan cheese, milk, thyme, salt and pepper; add into the tuna mixture and toss well to combine.
  5. Set oven to 350°F.
  6. Grease a 2-quart casserole dish.
  7. Spoon HALF of the mixture into prepared dish.
  8. Top with HALF of the sliced zucchini.
  9. Then sprinkle with cheddar cheese.
  10. Top with noodle mixture then remaining zucchini.
  11. Sprinkle with more grated Parmesan cheese if desired.
  12. Bake covered with foil for 30 minutes.
  13. Remove from oven and uncover, sprinkle with grated mozzarella cheese, return to oven (uncovered) and bake for another 10 minutes.
  14. Sprinkle chopped tomato over casserole before serving.