Community Pick

Kittencal's Tuna-Spaghetti Casserole

Want more from Genius Kitchen?

Watch on your Apple TV, Roku, or Fire TV and your iOS, Fire, or Android device.

Learn More
“This is a recipe I developed years ago; it also works well using cooked chicken or turkey. Prep time includes boiling the spaghetti, adjust all ingredient amounts to taste, the cayenne may be omitted if desired and two cans of sliced drained mushrooms may be substituted for fresh :)”

Ingredients Nutrition

  • 8 ounces spaghetti, pieces (I usually just use a large handful of spaghetti, use the regular not thin or angel hair)
  • 14 cup butter (can use a little more butter when frying)
  • 12 lb fresh sliced mushrooms
  • 1 medium onion, chopped
  • 2 tablespoons fresh minced garlic (or to taste)
  • 14 teaspoon cayenne (optional or adjust to taste)
  • 5 tablespoons all-purpose flour
  • 2 -4 teaspoons chicken bouillon powder (I just use 1 small package OXO bouillon powder)
  • 2 cups good-quality chicken broth
  • 1 cup half-and-half cream (or use 18% table cream)
  • 13 cup grated parmesan cheese (or use 1-1/2 cups grated cheddar cheese)
  • salt & freshly ground black pepper (to taste, I use seasoned salt)
  • 2 (170 g) cans tuna (drained and hand-squeezed to remove any moisture)
  • 1 green bell pepper, seeded and chopped
  • 2 egg yolks
  • 1 cup grated cheddar cheese (optional or to taste)


  1. Butter a 13 x 9-inch baking dish.
  2. Chop the spaghetti coarsely. (I usually chop about 4-inches but it does not have to be exact).
  3. Cook the spaghetti until firm-tender (do not overcook the pasta!) drain and toss with 1-2 tablespoons butter or oil to prevent sticking.
  4. In a saucepan melt 1/4 cup butter over medium heat (can use a couple tablespoons more butter if desired, I always do!) add in the sliced mushrooms and cook stirring until they release their moisture (about 6 minutes).
  5. Add in onion, garlic and cayenne pepper; sauté for about 3 minutes.
  6. Add in flour and chicken bouillon powder; mix with a wooden spoon for about 1-2 minutes (the mixture will be slightly "clumpy").
  7. Stir in the broth and cream; bring to a light boil over medium heat whisking continuously until smooth and thickened.
  8. Turn off heat and stir in the Parmesan cheese (or cheddar cheese if using) mix to combine until melted.
  9. Season sauce with salt and black pepper (I use seasoned salt).
  10. Add the cooked cream mixture to the cooked spaghetti; toss well to combine, then add in the tuna, green bell pepper and egg yolks; mix very well to combine.
  11. Transfer the mixture to a prepared baking dish.
  12. Top with additional Parmesan cheese if desired.
  13. Bake for 30-35 minutes in a 350°F oven (oven rack set to second-lowest position).
  14. If desired you may sprinkle about 1 cup (or more) grated cheddar cheese on top after baking but that is only optional.

Watch more

Join the Conversation

  • all
  • reviews
  • tweaks
  • q & a