Brandy, Cream and Mushroom Sauce:
I griddle my steaks and then place them in a warmer. I add about 1/2 cup brandy to the griddle pan and reduce it (boil for about 1min) until there are about 1 or 2 tablespoons left, I then stir it to collect all the meat juices into the brandy, add a large dollop of creme fraiche, salt and black pepper and stir in some previously cooked sliced mushrooms. Pour over the steak - Absolutely delicious and very easy.
P.S. Use cheap brandy! I also add crushed garlic, but for those garlic haters this is not essential.