Preheat the oven to 375°F (190°C). Grease a baking dish and set aside.
In a large pot, cook the egg noodles according to package instructions, then drain and set aside.
In a mixing bowl, whisk together the cream of mushroom soup, milk, chicken broth, and shredded cheese until smooth.
Stir in the cooked noodles, flaked tuna, and frozen peas, mixing until everything is evenly coated.
Transfer the mixture to the prepared baking dish, spreading it out evenly.
In a small bowl, mix breadcrumbs with melted butter, then sprinkle evenly over the top.
Bake for 25-30 minutes, until the top is golden brown and the casserole is bubbling.
Let cool for 5 minutes before serving.
