Prepare the Beef: Season the beef with salt, pepper, garlic powder, and onion powder. Place it in the crockpot.
Build the Gravy: Add Worcestershire sauce, beef broth, and the Gravy Packet to the slow cooker. Stir in the cream of mushroom soup if using.
Slow Cook: Cover and cook on low for 6-8 hours or high for 4-5 hours, until the beef is tender and shreds easily.
Cook the Noodles: About 30 minutes before serving, cook the egg noodles separately according to package instructions. Drain and toss with butter and salt.
Combine & Serve: Stir the cooked noodles into the crockpot with the beef and sauce. Let everything sit for 5 minutes before serving.