This post may contain affiliate links. Please read our disclosure policy.
A lightened up version of the comfort food favorite, this Healthy Tuna Noodle Casserole recipe boasts all the classic creamy, cheesy character. Featuring fresher ingredients yet with all the hearty appeal, it will become an instant family favorite. 
Why You’ll Love this Healthy Tuna Noodle Casserole:
If you grew up in the 80’s or 90’s, I can only hope and assume that tuna noodle casserole was a classic dinner contender. The traditional casserole features a cast of heavy characters, such as cream of mushroom (or celery) soup, cheese, and a potato chip or fried onion topping.
This version, however, features a homemade cream of mushroom mixture, and is bolstered by lots of fresh herbs and aromatics. We also lean on whole wheat egg noodles to up the fiber ante. Canned tuna, however, still takes center stage, which is a fabulous and convenient source of beneficial omega-3 fatty acids.
This healthy homemade tuna casserole is MILES ahead of the classic in terms of freshness and flavor. Both kids and adults will love it, and not a single taster will guess it’s a lightened up version.
Plus, it makes the most fantastic leftovers, so consider dinner tonight and lunch tomorrow DONE.
Recipe Ingredients and Substitutions:
- Tuna: When purchasing canned tuna, look for the words “pole-and-line caught” on the label for the more sustainably-caught fish. My personal favorite is Wild Planet brand, which you can find at most well-stocked supermarkets. You can either use skipjack or albacore here–just make sure it’s packed in water and not oil.
- Noodles: I love using whole-wheat egg noodles, which offer a bit more fiber and B-vitamins. If you can’t find them, however, classic egg noodles are just fine!
- Aromatics: Onions, garlic, and fresh thyme create the aromatic backbone of this tuna noodle casserole. You can also use leeks here (either in lieu of, or in addition to the yellow onion), which are a fabulous compliment to the filling.
- Mushrooms: Cremini mushrooms bolster the filling with meaty, umami-rich goodness. Plus, they add extra vitamin D.
- Peas: Frozen green peas add a pop of color and burst of sweetness to the filling. You don’t have to completely thaw them, however they should be partially thawed before being mixed in the filling. You can also leave them out, if you’re not a fan.
- Milk: I prefer using whole milk for its rich, creamy character, however unsweetened cashew milk also works as a dairy-free alternative.
- Cheese: A little sharp white cheddar goes a long way in terms of richness and sharp, salty flavor. If making the casserole dairy-free, you can omit the cheese entirely, or swap it for nutritional yeast or dairy-free cheesy shreds.
- Breadcrumbs: For a crunchy, crave-worthy finish, sprinkle Panko breadcrumbs overtop right before baking. And if you prefer a crispier, golden topping (who doesn’t?!), turn the broiler to high for the final two minutes. For a gluten free alternative, use Ian’s Gluten Free Panko or crushed Rice Chex cereal.
Step-by-Step Instructions:
Step 1: Boil the Noodles
Preheat oven to 375°F and lightly coat a 9×13-inch baking dish with non-stick spray. Cook noodles according to package instructions in a large pot of salted water until very al dente. Drain, and transfer noodles back to pot removed from burner.
Step 2: Sauté Vegetables
Heat oil in a large high-sided skillet over medium-high. Add mushrooms and onion; cook until softened, about 8 minutes. Stir in garlic and fresh thyme; cook until fragrant, about 1 more minute. 
Step 3: Make a Roux
Add butter to pan; stir to melt. Sprinkle flour over mixture, and stir well to coat. Cook 2 full minutes to eliminate raw flour taste. Whisking constantly, gradually pour in vegetable broth; bring to a boil. 
Step 4: Add Milk and Cheese
Reduce to a simmer; whisk in milk, Dijon mustard, salt, pepper, and celery seed. Return to a simmer; simmer 3 minutes, or until slightly thickened. Sprinkle in half of the cheese and stir constantly until melted. Add lemon juice and zest. 
Step 4: Combine Tuna Noodle Casserole Ingredients
Step 5: Bake Casserole
FAQs and Expert Tips:
Is Canned Tuna Good for You?
Canned tuna sometimes gets a bad rap because of concerns over mercury, but there are easy ways to keep it in check. Mercury magnifies the higher up in the food chain we go, so larger fish often have higher amounts. For lower mercury levels, opt for smaller tuna fish—like light or skipjack tuna—over larger fish, like albacore and yellowfin.
Now let’s talk nutritional perks of tuna, which, in my opinion, far outweigh the mercury concerns. It’s high in protein and a great source of heart-healthy omega-3 fatty acids DHA and EPA. These fats are essential, meaning our bodies can’t make them and, therefore, we must get them from our diet.
The American Heart Association recommends we eat two (3- to 5-oz.) seafood servings every week to help reach our daily recommend dose of omega-3s, however only 1 out of every 10 Americans actually meets that quota. Beyond heart health, research also suggests that omega-3s support brain, eye, skin, and hair health as well.
How to Store and Reheat:
- To Store: Transfer leftovers in an airtight storage container and refrigerator for up to 4 days.
- To Reheat: Reheat individual portions gently in the microwave in 30 second intervals, stirring in between, until warm. Alternatively, reheat in a casserole dish in the oven at 350ºF. If using the oven, loosely tent the casserole pan with foil and place the pan on the center rack for 15 to 25 minutes, until warmed through (the larger the serving, the longer you will need).
- To Freeze: Place leftovers in an airtight freezer-safe storage container in the freezer for up to 3 months. Let thaw overnight in the refrigerator before reheating.
Recommended Tools to Make Tuna Noodle Casserole:
- Baking Dish: I love my Le Creuset dish for casseroles, however this one by Cuisinart is also fantastic quality and value.
- Sauté Pan: A high-sided sauté pan is best to avoid spill over.
- Silicone Whisk: For whisking the roux without scraping or damaging the pan, a silicone whisk is best.
More Healthy Casserole Recipes:
-
Spaghetti Squash Casserole with Mushrooms and Goat Cheese
-
Mexican Casserole with Walnut Chorizo
-
One Pan Wild Rice and Cheesy Broccoli Casserole
-
Quinoa Enchilada Bake
If you give this tuna noodle casserole recipe a try, snap a pic and tag #dishingouthealth so I can see your beautiful creations. Also, follow along on Facebook and Pinterest for the latest recipe updates!
Healthy Tuna Noodle Casserole
Equipment
- Large stock pot
- Large sauté pan
Ingredients
- 12 oz. dry whole-wheat egg noodles (sub regular egg noodles)
- 2 Tbsp. olive oil
- 8 oz. sliced baby bella (cremini) mushrooms
- 1 1/2 cups finely chopped yellow onion
- 3 garlic cloves, minced
- 1 Tbsp. fresh thyme leaves, plus more for garnish
- 2 Tbsp. unsalted butter
- 3 Tbsp. all-purpose flour
- 2 cups vegetable broth
- 2 cups whole milk (sub unsweetened cashew milk)
- 2 tsp. Dijon mustard
- 1 tsp. kosher salt
- 1/2 tsp. black pepper
- 1/4 tsp. celery seed
- 1 cup freshly grated sharp white cheddar cheese, divided
- Zest and juice of 1 lemon
- 3 (4-oz.) cans unsalted albacore or skipjack tuna in water, drained
- 1 cup frozen green peas, partially thawed
- 1/2 cup panko breadcrumbs
Instructions
- Preheat oven to 375°F and lightly coat a 9x13-inch baking dish with non-stick spray. Cook noodles according to package instructions in a large pot of salted water until very al dente. Drain, and transfer noodles back to pot (removed from burner).
- Heat oil in a large sauté pan over medium-high. Once hot, add mushrooms and onion; cook until softened, about 8 minutes. Stir in garlic and fresh thyme; cook until fragrant, about 1 more minute. Add butter to pan; stir to melt. Sprinkle flour over mixture, and stir well to coat. Cook 2 full minutes, stirring often, to eliminate raw flour taste. Whisking constantly, gradually pour in vegetable broth; bring to a boil.
- Reduce to a simmer and gradually whisk in milk, Dijon mustard, salt, pepper, and celery seed. Bring mixture back to a simmer; simmer 3 minutes, or until slightly thickened. Sprinkle in half of the cheese and stir constantly until melted. Add lemon juice and zest. Pour milk mixture into pot with cooked noodles; add tuna and green peas. Stir well until all components are well-combined. Transfer mixture to prepared baking dish; sprinkle remaining cheese and breadcrumbs overtop.
- Bake casserole at 375°F until bubbly and cheese is melted, about 15 minutes. For a crisper, golden topping, broil for final 2 minutes. Let stand at room temperature 5 to 10 minutes before digging in. Garnish with additional fresh thyme, if desired.
Video
Notes
Nutrition
I calculate these values by hand to ensure accuracy, however expect up to a 10% variable depending on food brands.
We love this recipe as written, but this time I did shake it up and used nutritional yeast in place of the cheese. It was still just as tasty.