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Adult Tuna Casserole at

OK, I admit it. I like the old fashioned canned soup versions of casseroles (see Tuna Bake). However, that doesn’t mean I won’t kick up my game a bit and make a casserole that has more refined flavours and textures, for example, Adult Tuna Casserole.

I made this with Swiss instead of cheddar because I think it makes a better match to the creamy texture of this casserole. You could use cheddar, gouda, gruyere, fontina or any other cheese you like.

I started by cutting my vegetables and grating my cheese.

Adult Tuna Casserole 1

I heated the oil and sauteed the onions until they were soft. Then I added the mushrooms and sauteed until they gave off most of their liquid, about 3 minutes.

Adult Tuna Casserole 2

I added the butter and stirred until it melted. Then I added the flour and stirred until it was mixed with the melted butter.

Adult Tuna Casserole 3

I slowly poured in the milk and stirred until the sauce started to thicken. Then I added 375 ml (1 1/2 cups) of the cheese and dill. When the cheese is melted and incorporated, take it off the heat.

Adult Tuna Casserole 4

I sprayed my casserole dish with baking spray. I put 1/2 the rice in the casserole. I added the one can of the tuna and 1/2 of the green beans. I put 1/2 of the mushroom/cheese sauce over that and then 1/2 of the remaining cheese.

Adult Tuna Casserole 5

Repeat the layers with the remaining ingredients.

Adult Tuna Casserole 6

I baked it in a 350 F oven for 45 minutes.

Adult Tuna Casserole 7

We served it with Broccoli Salad.

The Verdict

This casserole has a nice creamy texture from using rice instead of noodles. The texture is reminiscent of risotto. The Swiss cheese adds to that creaminess and gives a deep rich flavour. The flavours aren’t strong enough to scare kids off but do lean more toward sophisticated adult tastes. Spoil yourself. Make an adult casserole.

The Old Fat Guy

Adult Tuna Casserole

Yield: 4 servings

Adult Tuna Casserole


  • 375 ml (1 1/2 cups) cooked rice
  • 15 ml (1 tablespoon) vegetable oil
  • 125 ml (1/2 cup) diced onion
  • 250 ml (1 cup) diced mushroom
  • 50 ml (1/4 cup) butter
  • 50 ml (1/4 cup) flour
  • 550 ml (2 1/4 cups) milk
  • 5 ml (1 teaspoon) dried dill
  • 750 ml (3 cups) grated Swiss cheese, divided
  • 2 cans flaked tuna
  • 375 ml (1 1/2 cups) chopped vegetables (I used green beans)


  1. Preheat oven to 350 F.
  2. Heat the oil in a large fry pan over medium heat.
  3. Saute the onions, just until soft, about 3 minutes
  4. Add the mushrooms and cook until they give off some liquid, about 3 minutes.
  5. Add the butter and stir until melted.
  6. Add the flour and stir until mixed into the butter.
  7. Slowly stir in the milk.
  8. Stir constantly until the sauce thickens.
  9. Stir in 375 ml (1 1/2 cups) of the cheese and the dill.
  10. When the cheese is incorporated, remove from heat and set aside.
  11. Spray a casserole dish with baking spray.
  12. Put 1/2 of the rice in the bottom of the casserole.
  13. Add a layer of 1/2 of the tuna.
  14. Add a layer of 1/2 of the vegetables.
  15. Add a layer of 1/2 of the mushroom/cheese sauce.
  16. Add a layer of 1/2 of the remaining cheese.
  17. Repeat the layers with the remaining ingredients.
  18. Bake for 45 minutes.
  19. Let sit for 10 minutes before serving.
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