Vegan Tuna Casserole

vegan mini tuna casserole

♫ Listening to: Two Lips by Choir Boy ♫

My mom made me tuna casserole when I was growing up, and it was one of my favorite meals. This is my healthy(ish) vegan version of that casserole. It’s still one of my favorite meals, and now it’s healthier and cruelty free. I think this recipe would be mom-approved. If you like comfort food, you might also like this recipe.

This recipe makes 1 large lasagna pan of casserole or lots of mini casseroles if you prefer tiny cute things.

Vegan Tuna Casserole Ingredients

Dollhouse Shortcut

If you don't have an onion, you can instead add 1 teaspoon of onion powder when you add the garlic powder.

  • 1 onion, finely diced
  • 2-3 tablespoons of olive oil (if you avoid oil, replace this with water)
  • 1 pound of mushrooms, washed and sliced
  • ¼ cup unbleached flour
  • 1 ½ cups filtered water, boiling
  • ½ cup nutritional yeast
  • 1 teaspoon garlic powder
  • 1 teaspoon pepper
  • 2 teaspoons pink sea salt
  • 2 tablespoons organic tamari or soy sauce*
  • 1-2 cups grated vegan cheese (optional, but I used 1 ½ cups of violife cheddar)
  • 16 ounces pasta*
  • 1 bag (1 pound) of frozen peas
  • 1 package of vegan tuna, shredded (I like the one made by Layonna Vegetarian the best because it doesn't taste fishy. I've also used chickpeas in the place of tuna.)

Vegan Tuna Casserole Directions

prep time: 15 minutes; cook time: 45 minutes; total time: 1 hour

Boil a large pot of water. You’ll add the pasta as soon as it starts to boil, but while you wait for that, you can start on the cheesy mushroom gravy sauce.

Heat 1-2 cups of water in a kettle. You’ll use this for the cheese sauce gravy combo.

Dice half of the mushrooms finely.

Sauté the finely diced onion and mushrooms in a saucepan with olive oil with the lid on over medium heat for around 10 minutes. If you avoid oil, replace it with water.

Blend ¼ cup unbleached flour with 1 ½ cups filtered boiling water and 2 tablespoons of tamari (or soy sauce).

Whisk the blended mixture into the sauteéd mushrooms and onion until you have a thick sauce consistency (this can take up to 10 minutes, but usually just a few).

Add the remaining dry ingredients: ½ cup nutritional yeast, 1 teaspoon garlic powder, 2 teaspoons sea salt, and 1 teaspoon pepper. Continue whisking.

Add the grated vegan cheese, handful by handful, whisking until smooth in between each addition. Turn heat off once the sauce is smooth(ish). This step is optional so skip it if you don’t care for processed vegan cheese or use homemade cheese.

Heat the oven to 350°.

Add the pasta to the boiling water, and boil for the amount of time on the package directions.

Stir the pasta after 1 minute to make sure it isn’t sticking to the bottom of the pot.

Scoop the pasta from the boiling water and dump it into a colander in the sink, using a slotted spoon.

Return the pot to the stove over high heat, add the frozen peas, and bring to a boil again.

Boil peas for 4-5 minutes.

Drain the peas by pouring the contents of the pot into the colander that’s been holding the pasta.

Transfer the pasta and peas back into the empty pot.

Add the sliced mushrooms and stir.

Add the mushroom onion cheese sauce to the pasta, and mix thoroughly. This gravy-like sauce takes the place of the can of mushroom soup plus the can of milk plus the cheese that my mom’s recipe traditionally called for.

Add the tuna to the pot and mix thoroughly. (If your tuna didn’t come shredded, you’ll have to shred it in the food processor before adding it to the pasta.)

At this point, you can stop and serve the pasta if you’re too hungry to wait any longer. But if you want it to taste like my mommy’s tuna casserole, you have to go the extra step.

Transfer to a lasagna pan or other oven safe dishes. I made a cute tiny heart one for me and a bigger one for everyone else.

Top with breadcrumbs, chip crumbs, cracker crumbs, fried onions, or whatever casserole topping you have lying around. You can also top with nothing or extra grated vegan cheese.

Bake in the oven at 350° for 15-20 minutes.

vegan tuna casserole in a heart shaped dish

bite of vegan tuna casserole

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* Whenever you see colored pasta in stores, make sure it’s colored with vegetables before you buy it. Some pasta is colored with squid ink! Poor little squid.

I use mostly organic ingredients when I cook, but I realize that not everyone has the disposable income to purchase all organic ingredients. Therefore, I only specify organic on the ingredients that really matter - when buying the organic version is the only way to ensure that the item is vegan.

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