This is tuna noodle casserole made fully from scratch. There is no canned soup here. A simple butter and flour sauce with milk and Parmesan coats the pasta and tuna, then it all bakes until hot and bubbly.

It feeds four, uses mostly pantry staples, and takes about 50 minutes from start to finish. If you grew up on the canned soup version, this one tastes cleaner and creamier, and you know exactly what is in it.

Why This Tuna Casserole Works

The secret is the roux. Cooking butter and flour together for a minute takes away the raw flour taste. When you whisk in the milk, the flour thickens it into a smooth white sauce. This is the same base used for mac and cheese and many other creamy bakes.

Parmesan gives the sauce a salty, savory flavor that canned soup can’t match. Garlic powder adds depth without extra chopping. The pasta and tuna soak up the sauce in the oven, so every bite is creamy.

Ingredients and Easy Swaps

• Elbow macaroni: 12 ounces. Wide egg noodles are the classic choice and work just as well. Small shells or rotini are good too.
• Butter and flour: 2 tablespoons of each for the roux.
• Whole milk: 2 cups. Whole milk gives the richest sauce. 2% works, but the sauce will be a little thinner.
• Parmesan: ½ cup, grated. Freshly grated melts best.
• Seasonings: Garlic powder, salt, and black pepper.
• Tuna: Two 5 ounce cans, drained and flaked. Tuna packed in water or oil both work. Oil-packed tuna is a bit richer.
• Frozen peas or corn: 1 cup, optional. No need to thaw them first.
• Cheese topping: ½ cup shredded mozzarella or cheddar, optional.

How to Make It at a Glance

1. Cook the macaroni according to the package, then drain.
2. Melt the butter in a saucepan, stir in the flour, and cook for 1 minute.
3. Slowly whisk in the milk and cook 3 to 5 minutes until thick. Stir in the Parmesan, garlic powder, salt, and pepper.
4. Gently mix the pasta, tuna, vegetables, and sauce in a large bowl.
5. Spread in a greased 9×13 inch dish and add the cheese if using.
6. Bake at 375°F for 20 to 25 minutes until hot and bubbly.

Common Mistakes to Avoid

Adding the milk all at once. Pour it in a little at a time and whisk the whole time. This keeps lumps from forming.

Overcooking the pasta. The pasta keeps cooking in the oven. Pull it a minute before the package time so it doesn’t turn mushy.

Not draining the tuna well. Extra liquid thins the sauce and makes the casserole watery. Press the lid down firmly on the can to squeeze it out.

Stirring too hard. Fold the tuna in gently so it stays in nice flakes instead of turning into paste.

Variations

• Crunchy top: Toss ½ cup panko with a tablespoon of melted butter and sprinkle it over the top before baking.
• Mushroom: Sauté 8 ounces of sliced mushrooms in the butter before adding the flour.
• Extra cheesy: Stir ½ cup shredded sharp cheddar into the sauce with the Parmesan.
• Swap the protein: Use canned salmon or shredded cooked chicken in place of tuna.

What to Serve With It

This casserole is rich, so pair it with something fresh. A green salad with a lemony dressing, steamed green beans, or roasted broccoli all work well. Sliced cucumbers or a quick coleslaw add crunch. For a bigger meal, add warm dinner rolls.

Make Ahead, Storage, and Reheating

Make ahead: Assemble the casserole, cover it tightly, and refrigerate for up to 24 hours. Add 5 to 10 minutes to the bake time since it starts cold.

Storage: Keep leftovers covered in the fridge for up to 3 days. You can freeze it for up to 2 months, though the sauce may be a little less smooth after thawing.

Reheating: Add a splash of milk, cover with foil, and warm at 350°F for about 20 minutes. Single servings reheat well in the microwave.

FAQ

Can I use egg noodles instead of macaroni?
Yes. Use 12 ounces of wide egg noodles and cook them just shy of done.

Why is my sauce lumpy?
The milk was likely added too fast. Whisk hard over low heat and most lumps will smooth out.

Can I make it gluten-free?
Use gluten-free pasta and a one-to-one gluten-free flour blend for the roux.

My casserole turned out dry. What happened?
The pasta soaked up the sauce. Next time, keep the pasta slightly firm, or add an extra ½ cup of milk to the sauce.

Can I use canned chicken instead of tuna?
Yes. Two 5 ounce cans of chicken, drained, work the same way.

Tips for the Best Results

• Use a whisk, not a spoon, for the roux and milk. It keeps the sauce smooth.
• Warm the milk slightly before adding it. Cold milk can make the roux seize up.
• Taste the sauce before mixing it with the pasta. Add a pinch more salt if needed.
• Let the casserole rest 5 minutes out of the oven so the sauce thickens.

Budget Tips

This casserole is made from cheap pantry staples. Canned tuna, dry pasta, milk, butter, and frozen peas cost very little, especially in store brands. Buy a wedge of Parmesan instead of the shaker kind. It lasts for weeks in the fridge and tastes much better. A single 9×13 pan feeds four with leftovers for lunch.