Tuna Casserole
Creamy tuna noodle casserole with peas, mushrooms, and crunchy topping.
Updated: Oct 7, 2026
Why you'll like it
- Ready in about 50 minutes.
- Serves 6 — easy to halve or double.
- Easy level — everyday equipment only.
- Storage, freezing and reheating covered below.
Tuna Casserole takes about 50 minutes and serves 6. Tuna casserole is an economical baked dinner made with egg noodles, canned tuna, peas, and a creamy mushroom sauce.
Helpful guides
Instructions
Preheat the oven to 375°F and grease a 9x13-inch baking dish. Cook egg noodles in salted boiling water 2 minutes less than package directions so they finish in the oven without becoming mushy. Drain well.
In a large saucepan, melt butter over medium heat. Add flour and whisk 1 minute to form a smooth paste. Gradually whisk in milk and cook 4 to 5 minutes, stirring, until thickened enough to coat a spoon.
Stir in salt, pepper, 1/2 teaspoon garlic powder, and cheddar until melted. Fold in drained tuna, peas, and mushrooms. Add drained noodles and toss gently to coat evenly without breaking the noodles.
Spread the mixture evenly in the prepared dish. Sprinkle crushed chips or breadcrumbs over the top and dot with 1 tablespoon melted butter if using breadcrumbs for extra browning and crunch.
Bake uncovered for 25 to 30 minutes until bubbling at the edges, golden on top, and steaming in the center. Fish and dairy should be heated through; the center should be visibly hot and reach 165°F.
Rest 5 to 10 minutes before serving so the sauce sets for cleaner scoops. Serve warm with salad or vegetables. Cool leftovers quickly and reheat portions until steaming and reaching 165°F throughout.
Troubleshooting — fixes, not repeats
- If casserole is dry, undercook noodles slightly and ensure sauce is creamy before baking; add 1/2 cup milk if mixture looks stiff.
- If topping browns too fast, tent loosely with foil and continue baking until the center bubbles and reaches temperature.
- If bland, add salt gradually plus 1 teaspoon Dijon mustard or lemon juice to brighten the creamy sauce.
- If watery, drain tuna and noodles thoroughly; excess liquid thins the sauce and prevents proper setting.
Make it your way
- For a canned-soup version, replace butter, flour, and milk with 2 cans cream of mushroom soup plus 1 cup milk.
- For a vegetable version, add 1 cup diced celery and 1 cup chopped bell pepper sauteed in butter.
- Use salmon instead of tuna for a different flavor.
Storage & reheating
Cool leftovers within 2 hours, then refrigerate in a covered container and use within 3 to 4 days. Reheat only the portion you will eat until steaming hot throughout — poultry and reheated rice should reach 165°F (74°C).
Reheat covered in a 350°F oven or microwave with a splash of milk until steaming and reaching 165°F.
Freeze portions for up to 2 months; thaw overnight in the refrigerator.
FAQ
Can I use canned soup?
Yes. Substitute 2 cans condensed cream of mushroom or celery soup plus 1 cup milk for the homemade sauce. Reduce added salt, as canned soup contains more sodium. Bake the same way.
What tuna is best?
Solid white albacore packed in water holds its shape and tastes mild. Drain well before folding into noodles. Oil-packed tuna works but should be drained thoroughly to avoid greasiness.
How do I reheat without drying?
Add a splash of milk, cover, and reheat until steaming and 165°F. The noodles absorb sauce overnight, so extra liquid restores creaminess. Stir halfway for even heating.