In a small bowl, combine the oil and Creole seasoning. Mix well. Spread each side of the steaks completely with the Creole seasoning mixture. Place in a shallow pan, cover with plastic wrap and refrigerate for at least 4 hours. Remove and bring to room temperature before grilling, about 30 minutes. Preheat the grill. In a saucepan, over medium heat, melt the butter. Add the shallots and garlic. Season with salt and pepper. Saute for 1 minute. Add the red wine and bring to a boil. Reduce the heat to medium and stir in the demi-glace. Simmer for 2 minutes and remove from the heat, keeping warm. Place the steaks on the grill and cook for about 4 to 6 minutes on each side for medium-rare. Remove from the grill and cool for a couple of minutes before serving. Place the steaks and potatoes on each serving plate. Spoon a quarter of the sauce over each steak. Garnish with parsley.
Combine all ingredients thoroughly.
Place the potatoes in a pot of salted water and bring to a boil. Reduce the heat to a simmer and cook the potatoes until fork tender, about 12 to 15 minutes. Remove the pan from the heat and drain. Place the potatoes back in the pot and return to the heat. Stir the potatoes, constantly, for 2 to 3 minutes to dehydrated the potatoes. Remove the potatoes from the heat. Add the butter. Using a hand-held masher, mash the butter into the potatoes. Add enough cream until desired smoothness is achieved. The potatoes should still be sort of lumpy. Season the potatoes with salt and pepper.