There are endless versions and recipes for classic steak Diane, a dish of seared steak served with a rich, creamy, and flambéed pan sauce. Each calls for different cuts of steak, and some include button mushrooms. There are debates of scallions versus shallots, chives versus parsley, veal demi-glace versus beef stock, tomato paste or no tomato paste.
This recipe is my personal interpretation of steak Diane. I believe that as long as it includes a cut of steak and that the sauce consists of Dijon mustard, Worcestershire sauce, beef stock, a dash of heavy cream, and flambeed cognac, it falls under the steak Diane umbrella.