Preheat your oven to 350°F (175°C) and lightly grease a standard 9×13-inch baking dish.
In a large skillet over medium heat, cook and crumble the ground beef for 5 to 7 minutes until fully browned and an instant-read thermometer reaches 160°F (71°C). Drain off excess grease, then season with the kosher salt and black pepper.
Bring a large pot of salted water to a rolling boil. Add the egg noodles and boil for 6 to 8 minutes until just al dente. Drain thoroughly in a colander.
In a large mixing bowl, gently fold together the cooked ground beef, drained egg noodles, condensed cream of mushroom soup, and thawed mixed vegetables until evenly coated.
Spread the mixture evenly into the prepared 9×13-inch baking dish. Sprinkle the shredded cheddar cheese evenly across the top. Cover tightly with aluminum foil.
Bake covered at 350°F (175°C) for 30 minutes. Remove the foil and bake uncovered for an additional 10 to 15 minutes until bubbly and golden brown, and the center reaches a safe internal temperature of 165°F (74°C).
Let the casserole rest on a wire rack for 10 to 15 minutes before slicing and serving so the layers set cleanly.