This easy tuna noodle casserole without cream of mushroom soup is the upgraded version of a classic! Made with real ingredients, and ready in under 30-minutes, this one pot meal is sure to be a hit with your family.
Make the roux. Start by melting the butter in a large saucepan, stock pot, or Dutch oven over medium. Add the flour and whisk for 1-3 minutes. We're making a "white roux" to thicken our sauce, so it should have an off-white to light tan color and the texture of wet sand.
Make the sauce and cook the noodles. Slowly add in the chicken broth to the roux, whisking continuously. Stir in the milk, salt, black pepper, and garlic powder. Bring the mixture to a low boil.
Add the noodles and peas and stir to combine. Bring the sauce back up to a low boil, and then reduce the heat to medium-low to simmer.
Cook for 8-10 minutes, stirring occasionally, until the noodles are soft and most of the mixture has been soaked up by the noodles.
Add in the tuna. Stir in the tuna to distribute throughout.