Classic Tuna Casserole

Why This Classic Tuna Casserole Works

Cream of mushroom soup and milk are the main reason this casserole works. During baking, the soup and milk heat up and turn into a thick, creamy sauce that coats the egg noodles and tuna. That sauce sinks into the noodles so they stay soft and moist instead of drying out in the oven. The tuna and peas sit in that same sauce, so they warm through gently and don’t get tough or shriveled.

As the casserole bakes, shredded cheddar melts all through the noodles and tuna. The cheese mixes into the sauce and makes it thicker and a little stretchy, so each scoop holds together instead of falling apart. Chopped onion softens in the heat and blends into the creamy mixture, so there are no harsh bites of raw onion.

On top, crushed potato chips toast in the oven. They stay crisp while everything under them stays soft and saucy. By the time it is done, there is a crunchy, salty top over a creamy, cozy noodle filling.

Mistakes To Avoid

Boiling the egg noodles until they are very soft instead of just al dente makes them fall apart in the oven. As the casserole bakes, the noodles soak up more liquid and turn mushy, so the whole dish ends up pasty instead of having separate, tender pieces.

Pouring in extra milk to make the mixture “creamier” leaves the casserole loose and soupy. In the oven, it never really sets, so scooping it out gives more of a wet noodle stew than slices that hold their shape.

Skipping the step of draining the tuna well lets a lot of extra water into the mix. During baking, that liquid thins the sauce and steams the noodles, so the top may brown but the inside stays watery and a bit bland, with the tuna flavor washed out.

Letting the casserole bake far past the 30-minute mark dries out the noodles and tuna. The top turns hard and overly crisp, and the inside loses its creamy texture, so each bite feels stiff and chalky instead of soft and comforting.