Classic No Noodle Tuna Casserole

Here is my favorite no noodle tuna casserole recipe, with tender vegetables, creamy sauce, melted cheese, and all the comfort food flavors you love, but without the pasta.

This tuna casserole is perfect for busy weeknights when you want something filling and satisfying. My kids actually prefer this version over the traditional noodle kind, and it’s become our go-to when we need dinner on the table fast.

What Kind of Tuna Should I Use?

For this no-noodle casserole, you’ll want to stick with water-packed tuna rather than oil-packed since it gives you better control over the moisture content. Both chunk light and solid white albacore work well, though chunk light tends to be more budget-friendly and has a milder flavor that pairs nicely with the other ingredients. If you’re concerned about mercury levels, chunk light is also the better choice since it typically contains less mercury than albacore. Make sure to drain your tuna really well before adding it to the casserole – you can even give it a gentle squeeze with paper towels to remove excess water and prevent your dish from getting soggy.

Options for Substitutions

This no-noodle casserole is pretty forgiving when it comes to swaps and substitutions:

• Tuna: You can easily swap the tuna for canned salmon, cooked chicken breast, or even leftover rotisserie chicken. Just make sure to drain any liquid and flake it into similar-sized pieces.
• Green beans: Don’t have green beans? Try frozen broccoli florets, asparagus pieces, or even cauliflower. Fresh vegetables work great too – just blanch them for a few minutes first to soften them up.
• Red bell pepper: Any color bell pepper works here, or you can use diced zucchini or yellow squash for a different flavor profile.
• Cheddar cheese: Feel free to mix it up with Swiss, mozzarella, or even a Mexican cheese blend. Just stick with good melting cheeses for the best texture.
• Almond meal: If you don’t have almond meal, regular all-purpose flour works just fine. You can also use coconut flour, but use only 1 tablespoon since it’s more absorbent.
• Mayonnaise: Greek yogurt or sour cream can replace the mayo for a lighter option, though the texture will be slightly different. Start with 3 tablespoons and add more if needed.

Watch Out for These Mistakes While Cooking

The biggest mistake with this no-noodle tuna casserole is not properly draining your tuna – excess water will make your casserole watery and prevent it from holding together, so press the tuna with paper towels after draining to remove every bit of moisture.

Another common error is undercooking your vegetables, especially the green beans, which should be tender before mixing with the other ingredients since they won’t have much time to soften in the oven.

Don’t skip seasoning each layer as you go – taste your vegetable mixture and tuna mixture separately before combining, and remember that the almond meal helps bind everything together, so don’t leave it out even if the amount seems small.

Finally, let the casserole rest for about 10 minutes after baking so it can set up properly and won’t fall apart when you serve it.

What to Serve With No Noodle Tuna Casserole?

This hearty casserole is pretty filling on its own, but I love serving it with a simple side salad to add some fresh greens to the meal. A basic mixed greens salad with cucumber and cherry tomatoes works perfectly, or you could go with a crisp Caesar salad for something a bit more substantial. Since the casserole is rich and cheesy, some crusty bread or dinner rolls are great for soaking up any extra flavors on your plate. For a lighter option, steamed broccoli or roasted asparagus pairs nicely with the tuna and cheese flavors without making the meal too heavy.

Storage Instructions

Refrigerate: This no noodle tuna casserole keeps really well in the fridge for up to 4 days in a covered container. I actually think it tastes even better the next day after all the flavors have had time to meld together. It’s perfect for meal prep lunches throughout the week.

Freeze: You can definitely freeze this casserole for up to 3 months in a freezer-safe dish or container. Just make sure it’s completely cooled first, and consider portioning it out into individual servings for easier thawing. The texture might be slightly different after freezing, but it’s still delicious.

Reheat: To warm up leftovers, just pop individual portions in the microwave for 1-2 minutes, or reheat the whole dish in a 350°F oven for about 15-20 minutes until heated through. You might want to add a sprinkle of extra cheese on top if it looks a bit dry after reheating.

Preparation Time	15-20 minutes
Cooking Time	20-25 minutes
Total Time	35-45 minutes
Level of Difficulty	Easy

Estimated Nutrition

Estimated nutrition for the whole recipe (without optional ingredients):

• Calories: 900-1050
• Protein: 120-135 g
• Fat: 45-55 g
• Carbohydrates: 15-20 g

Ingredients

For the vegetable mixture:

• 1/2 large red bell pepper (finely chopped)
• 1 large celery stalk (finely chopped into 1/4-inch pieces)
• 1 tbsp olive oil (or any neutral oil like avocado)
• 2 medium garlic cloves (minced)
• 1 cup green beans (fresh or thawed frozen, chopped into 1/2-inch pieces)
• 1/4 large red onion (finely chopped)

For the casserole:

• 20 oz water-packed tuna (drained well, flaked)
• 1 cup cheddar cheese (shredded, for better melting)
• 1/4 cup mayonnaise (I use Hellmann’s)

For the topping:

• Salt and black pepper to taste
• 2 tbsp almond meal (creates a crispy, golden crust)

Step 1: Prepare the Mise en Place

• 2 medium garlic cloves
• 1 large celery stalk
• 1/2 large red bell pepper
• 1/4 large red onion
• 1 cup green beans

Mince the garlic cloves and finely chop the celery, red bell pepper, red onion, and green beans into uniform sizes.

This ensures even cooking and a consistent texture throughout the casserole.

Having everything prepped before you start cooking allows you to work quickly once the pan is hot, which is crucial for developing flavor in the vegetables without overcooking them.

Step 2: Sauté the Vegetables

• 1 tbsp olive oil
• prepared vegetables from Step 1

Heat the olive oil in a skillet over medium-high heat.

Once shimmering, add all the prepped vegetables (onion, garlic, celery, bell pepper, and green beans) and cook for 5-7 minutes, stirring occasionally, until they become tender and the onions soften.

The vegetables will develop a subtle sweetness and the garlic will release its aromatic oils—this is where the casserole’s flavor foundation is built.

I like to cook them until they’re just tender but still have a slight firmness, as they’ll soften further during baking.

Step 3: Build the Casserole Base

• sautéed vegetables from Step 2
• 20 oz water-packed tuna
• 1/4 cup mayonnaise
• 1 cup cheddar cheese

In a large bowl, combine the sautéed vegetables from Step 2 with the drained and flaked tuna, mayonnaise, and shredded cheddar cheese.

Fold everything together gently until well combined, being careful not to break up the tuna too much—you want some texture and structure in the final dish.

The mayo acts as a binder and adds richness, while the cheese melts throughout during baking to create creamy pockets of flavor.

Step 4: Assemble and Top the Casserole

• casserole mixture from Step 3
• 2 tbsp almond meal

Transfer the tuna and vegetable mixture into a 9×13-inch baking dish (or similar-sized casserole dish), spreading it in an even layer.

Sprinkle the almond meal evenly across the top—this creates a crispy, golden crust that contrasts beautifully with the creamy filling beneath.

I prefer almond meal over traditional breadcrumbs because it adds a subtle nuttiness and keeps the casserole grain-free.

Step 5: Bake and Season

• assembled casserole from Step 4
• Salt and black pepper to taste

Bake the casserole at 350°F for 20-25 minutes, until the almond meal topping turns golden brown and the mixture is heated through.

Remove from the oven and let it cool for 5 minutes before serving—this allows the casserole to set slightly and makes it easier to portion.

Season to taste with salt and black pepper just before serving, adjusting as needed since the tuna and cheese already contribute some saltiness.