Timeless Tuna Casserole

Why This Timeless Tuna Casserole Works

During cooking, the egg noodles do most of the work holding everything together. They start out loose, but once they’re mixed with the cream of mushroom soup and milk, the starch on the noodles grabs onto the creamy sauce. As it heats, that sauce thickens and clings to each noodle, so the tuna, peas, and celery stay tucked into every bite instead of sliding around.

In the oven, the heat finishes setting the whole casserole. The soup and milk mixture goes from runny to more set, almost like a soft custard around the noodles and tuna. Nothing is dry, though, because the noodles soak up some liquid while the rest stays in the sauce. On top, the cheddar, parmesan, and breadcrumbs melt and toast together. The cheese melts down into the crumbs, and the crumbs soak up a bit of butter and moisture from below, so the top turns crisp and golden while the inside stays creamy and soft.

Mistakes To Avoid

Boiling the egg noodles until they are very soft makes the whole casserole mushy. Once baked in the sauce, the noodles keep soaking up liquid and break apart, so the dish turns pasty instead of having separate, tender pieces.

Pouring in extra milk or using a very thin milk makes the mixture too loose. In the oven, the sauce never really thickens around the noodles and tuna, so the casserole cuts into runny, soupy portions instead of firm squares.

Skipping the step of softening the onion, garlic, and celery in butter leaves them half-raw in the final bake. The short oven time is not enough to finish cooking them, so the casserole ends up with hard, crunchy bits in a soft, creamy base.

Stirring the tuna in too roughly breaks it into a fine paste. During baking, this paste blends into the sauce instead of staying in small chunks, so the texture turns uniform and slightly grainy instead of having clear bites of tuna.