Preheat oven to 350°F (175°C) and grease a 9x13 inch baking dish.
Cook egg noodles in a large pot of boiling salted water until al dente according to package instructions; drain and set aside.
In a large skillet over medium-high heat, brown the ground beef with the diced onion and bell pepper until the meat is fully cooked and vegetables are softened.
Add minced garlic, salt, pepper, and Worcestershire sauce to the skillet and cook for 1 minute.
In a large mixing bowl, combine the beef mixture, cooked noodles, cream of mushroom soup, and sour cream until well incorporated.
Transfer the mixture into the prepared baking dish and spread into an even layer.
Sprinkle the shredded cheddar cheese evenly over the top.
Bake in the preheated oven for 25 to 30 minutes until the casserole is bubbling and the cheese is melted and lightly golden.
Remove from oven and allow to rest for 5 minutes before serving.