Set the EGG for indirect cooking with the convEGGtor at 400°F/204°C.
Mix the flour, garlic powder, mustard powder and salt and pepper. Coat the steak in the flour mixture.
Heat the oil in a cast iron skillet and add the steak. When the steak is halfway cooked add the onion and mushrooms. Cook for approximately 10 minutes. Add the beef broth and cook until it has reduced and becomes thick, about 10 minutes. Mix in the sour cream and remove from the EGG.
Serve over noodles.