Gordon Ramsay's Steak Diane from Epicurious.com is a good recipe for steak with a creamy Diane sauce. The recipe serves four, and side dishes of peas and sauteed potatoes are recommend by the chef.
Flatten four 7-ounce sirloin steaks with a rolling pin, trim off any excess fat and season the meat to taste with salt and pepper. In a skillet large enough to fit all of the steaks in one layer, heat a little olive oil and saute the meat on both sides for up to a minute. Remove the sirloins and set them aside.
Make the creamy Diane sauce by heating a little olive oil in a separate pan and adding 3 sliced shallots. Let the shallots soften briefly and add 4 ounces of sliced crimini mushrooms and 1 tablespoon of butter. Stir in 1 clove of crushed garlic, 1 tablespoon of Dijon mustard and 1 to 2 tablespoons of Worcestershire sauce to suit your taste. Heat the mixture for about one minute, and then turn the heat and tilt the pan away from you Pour one-third of a cup of either brandy or cognac into the far end and let it ignite, being careful with the flames.
Swirl the remaining liquid around in the pan after the alcohol has burned off, and add 1 cup of heavy cream. After the sauce has thickened on high, turn down the heat and put the steaks in the pan, allowing them to cook to your desired level of doneness. Dress with a little chopped parsley and serve.