Remove steaks from packaging & fridge 1 hour before cooking. To make the vinaigrette, whisk together oil, lemon & jus then season to taste. Fold the chopped vegetables & tomato through the vinaigrette & reserve. Pre heat a griddle or heavy based frying pan large enough to hold the meat until it sizzles when you add a drop of oil. Season the steak liberally with sea salt just prior to cooking & massage with oil. Sear the steak on all sides over high heat creating a rich, dark crust then reduce to medium heat Cook 3 to 4 minutes each side basting the steak with foaming butter for the final couple of minutes of cooking. For a rare steak, press the steak with your thumb it should have a slight spring to touch & a core temperature of 50°C before resting. Alternatively you can pop the steak into a preheated oven (after the initial charring steps) 200°C /180°C fan assisted (gas 6) for 6-8 minutes.