When it comes to cooking and preparing steak for your dog to eat the best option is to keep things as simple as possible.
Your dog is not bothered at all about added spices or other flavourings and, in fact, you should never add anything as it could make your dog unwell.
The easiest option is to either grill, fry or barbecue steak for your dog, let it cool and then cut it up into bite sized chunks for your dog to eat.
Your dog will not be fussy over rare, medium rare or well done options but you should make sure that the steak is cooked through to make digestion easier.