Preheat Your Oven: Start by preheating your oven to 350°F (175°C). This will ensure that your casserole cooks evenly.
Cook the Noodles: Boil the egg noodles according to package instructions, then drain them and set aside.
Brown the Beef: In a large skillet, cook the ground beef and chopped onion over medium heat until the beef is browned and no longer pink. Drain excess fat.
Combine Ingredients: Stir in the cream of mushroom soup, beef broth, and sour cream. Mix until everything is well combined.
Mix in Noodles: Add the cooked noodles to the beef mixture, blending it all together.
Prepare for Baking: Pour the entire mixture into a greased 9x13 inch casserole dish.
Add Cheese and Toppings: Sprinkle shredded cheddar cheese over the top and add breadcrumbs if desired.
Bake: Place the casserole in the oven and bake for 30-40 minutes, or until it’s bubbling and golden on top.
Serve and Enjoy: Let it cool for a few minutes before digging in!