Preheat the oven to 350 degrees and lightly grease a 9 by 13 inch baking dish.
Cook the egg noodles in a large pot according to package directions, then drain and set aside.
In a large skillet over medium heat, brown the ground beef with the diced onion, minced garlic, and sliced mushrooms until the beef is cooked through and the vegetables are softened.
Stir in the cream of mushroom soup and beef broth, then season with salt and pepper to taste. Simmer for 2 to 3 minutes until the mixture is well combined.
Add the drained noodles to the skillet and stir until everything is evenly coated.
Transfer the mixture to the prepared baking dish and sprinkle the shredded Swiss cheese evenly over the top.
Bake for 20 minutes or until the cheese is melted and bubbly.