-Yellow Onion -Butter -Mushrooms -Salt -Pepper -Flour -Whole Milk -Tuna
-Chicken Broth -Cream Cheese -Frozen Peas -Wide Egg Noodles -Breadcrumbs -Parmesan
Start by finely dicing one yellow onion. Add it to a skillet with butter and sauté over medium until the onions are soft.
While the onions are sautéing, slice mushrooms. Add the mushrooms, salt, and pepper to the skillet with the onions and continue to sauté until they are tender. Transfer the sautéed vegetables to a clean bowl.
Add butter and flour to the skillet. Whisk together as the butter melts. Cook for about one minute after the butter and flour mixture begins to bubble and foam. This mixture helps thicken the sauce.
Add milk, vegetable broth, and cream cheese to the skillet. Continue to cook and whisk these ingredients together over medium heat until the cream cheese has fully melted and the sauce begins to simmer.
Add the cooked onions and mushrooms and frozen peas to the creamy sauce. Stir to combine. Taste and add more salt and pepper. Set the sauce aside.
Begin to preheat the oven to 350ºF. Bring a pot of water to a boil, then add 8oz. wide egg noodles. Boil for about 7 minutes, or just until tender. Drain the noodles in a colander.
While the pasta is boiling, mix together the Parmesan breadcrumb topping. Melt butter in a small bowl, then stir in breadcrumbs and grated Parmesan.
Finally, combine the creamy mushrooms sauce, cooked and drained egg noodles, and tuna. If you wanted to add cheddar, this is the point where I’d stir it into the mix.
Transfer the casserole mixture to a casserole dish and top with the Parmesan breadcrumb topping. Bake for about 25 minutes in 350ºF oven, or until heated through and golden brown on top.