Method 1. Remove the steak from the fridge for at least 20 minutes before cooking to bring to room temperature. While it comes to temperature, season the steak well with salt and pepper on both sides. Set on a wire rack over a roasting tray and leave uncovered, until you are ready to cook. 2. Preheat the oven to 140C. Place the steak in the oven for approximately 25-35 minutes for medium-rare its temperature should read 55C. 3. While the steak cooks, prepare the chips: place the potato chips in a large heavy-based casserole dish or Dutch oven and pour over the oil until it covers them. Place over a high heat and bring to a steady boil. Reduce the heat to medium and cook for 15 minutes before gently moving with a tongs to loosen any that are stuck to base. Continue to cook for a further 5 minutes or so, or until they turn golden brown.