Ultimate Tuna Noodle Casserole

First, preheat your oven to 375 degrees Fahrenheit (or 190 degrees Celsius). Next, take a moment to grease a standard-sized 9x13-inch baking dish with some non-stick cooking spray.

Now, fill a large pot with water and put it on the stovetop to boil. Add 3 teaspoons of salt and your egg noodles to the boiling water; cook until they are tender yet still have a bit of firmness in the middle, approximately 6 minutes. Remove the noodles from the water and set them aside for now.

In a large skillet, melt 2 tablespoons of butter over medium-high heat. Add 1 tablespoon of oil to the skillet and sauté sliced mushrooms and onions until they are soft and translucent, taking about 4 minutes. Add the remaining butter to the skillet and stir constantly until it's fully incorporated and melted. Sprinkle a small amount of flour over the vegetable mixture in the skillet and cook, stirring constantly, for just 1 minute. Then, stir in milk, stock, lemon juice, Dijon mustard, 1 teaspoon of salt, and pepper. Bring the mixture to a gentle simmer, stirring frequently, for 5 minutes. Stir in some additional lemon juice and Dijon mustard to taste.

Add the sauce mixture you just created back into your reserved egg noodles. Stir in 1 cup of shredded Cheddar cheese, frozen peas, and canned tuna. Pour the noodle mixture into your prepared baking dish and sprinkle the remaining Cheddar cheese over the top.

In a small bowl, combine some bread crumbs, 2 teaspoons of oil, and the remaining 1/4 teaspoon of salt. Sprinkle some paprika over the top for added flavor. Mix everything together until it's evenly distributed.

Place your casserole in the preheated oven and bake until it's golden brown and bubbly, taking about 25 to 30 minutes. Remove the casserole from the oven and sprinkle some chopped parsley over the top for a fresh touch. Serve warm and enjoy your delicious creation!