Heat 1 tablespoon of the oil and 1 tablespoon of the butter in a frying pan over a moderate heat. Season the steaks with salt and pepper and cook them in the fat to your taste. Pour off the fat from the pan and arrange the steaks on a warmed serving platter. Heat the Grand Marnier and pour it over the steaks. Light the Grand Marnier with a match. Pour the crÅme fraöche into the frying pan, along with the green peppercorns and heat gently. Dice the remaining butter and stir it into the cream sauce. Taste for seasoning. Pour the sauce over the steaks and serve immediately with sautÄed potatoes.