Preheat the Blackstone griddle to medium-high heat. Put a cast iron skillet directly on the griddle.
Sear the beef: Add olive oil or butter to the hot skillet. Add your beef cubes. Season with salt, pepper, and garlic powder. Sear until browned on all sides (5–7 minutes).
Add liquids: Add diced onions (if using) and cook 2–3 minutes. Pour in beef broth to cover the meat. Add Worcestershire sauce and gravy mix. Stir well. Reduce heat to medium-low and let simmer 15–20 minutes to tenderize the beef.
Add egg noodles: Stir in uncooked egg noodles directly into the skillet. Add more broth or water as needed to keep noodles submerged. Cover loosely with foil or a lid and simmer until noodles are soft (about 10–12 minutes), stirring occasionally.
Finish it up: Let it simmer uncovered a bit to thicken the sauce. Taste and adjust seasoning.