I saw a card for this so gave it a try today. The blue cheese goes so good with steak. You don't need any dressing, just the steak and blue cheese are enough to make this one of the best sandwiches I've every made!
Salt & pepper the steak, high heat, olive oil the pan. Grill one side 2~3min. turn over and then add in butter, garlic and rosemary. Off the pan and let it sit while you prep the sandwich.
Get a loaf of multigrain bread. Cut large pieces and toast. (Not too long). After toasting, place blue cheese on one side of the toast and throw them into the oven until the cheese begins to melt.
Put them together and that's it!