For the crowning glory: the topping. In a small bowl, I mix the panko breadcrumbs with the remaining 1/2 cup of shredded cheddar. I sprinkle this mixture evenly over the entire surface of the casserole. This creates the ultimate crispy, cheesy crust as it bakes. I place the dish in the oven and bake for 25-30 minutes, until the filling is bubbly around the edges and the topping is a deep, golden brown. The smell is absolutely intoxicating. I let it rest for 10 minutes before serving—this helps it set for perfect slices.
Pro Tips for Best Results
Undercook your noodles! This is the single best tip for a perfect texture. Boiling them fully before baking leads to a mushy, over-soft final dish. Taking them out a minute or two early ensures they stay perfectly tender after absorbing the sauce in the oven. I always set a timer.
For a richer, more homemade sauce flavor, consider making a quick roux. Instead of using all the soup, you can melt the butter, whisk in 3 tablespoons of flour to make a paste, then slowly whisk in 2 cups of milk and a cup of chicken broth until thick. Stir in the cheese and seasonings. It’s an extra step, but the flavor payoff is incredible.
Let the casserole rest after baking. I know it’s hard to wait when it smells so good, but those 10 minutes allow the sauce to thicken and set. Cutting into it immediately will result in a soupy plate. The resting time is what gives you those beautiful, clean serving squares.
Common Mistakes to Avoid
My first casserole was a soggy disappointment because I used hot, just-drained noodles and didn’t toss them with butter. They continued to steam and absorb too much liquid, making the whole dish wet. Draining well and coating with a little fat creates a barrier. Also, make sure your tuna is thoroughly drained—squeeze it in the can or press it in a colander.(See the next page below to continue…)