Plan ahead, as cooking time is 4 hours including resting of the meat.
That said it is going to take you 2 minutes to do the prep, aside from the veggies. But you do need to plan well in advance. You can have all the roasting veggies scrubbed, oiled and salted in another roasting dish, ready to pop in the oven as the meat comes out.
Firstly, a small lesson in how meat should be treated prior to cooking, to which you need to bring out the piece of meat from the refrigerator several hours beforehand to bring up to room temperature. If you are in a temperate climate, this would be a least 6 hours however in the tropics about 3 hours should be sufficient. If I am sounding over-fastidious, it's all about treating the meat right to get the most out of it.
Preheat the oven to no more than 100 degrees Celsius, preferably around 80 or so. Ideally you will need an oven thermometer for this. You can source these from your kitchen supply shop.
Back to the oven, if you have a convection or fan oven, you need only set the temperature at around 50 degrees, as these ovens cook more effectively and evenly. Indeed you should always reduce the temperature by about 30 degrees Celsius with convection ovens as the air circulation created by the fan not only makes the heat more even and effective, it eliminates the thin layer of air that would otherwise surround the food, hence why these ovens are so popular. The strategic issue is not to let the oven temperature rise too much and subsequently negate the whole method of slow roasting.
Take a large metal oven roasting dish, placing the metal rack inside for the meat to sit on. Why the metal rack? This is simply another basic cooking tip that improves the flow of heat around the meat, indeed it prevents the meat being overcooked from the bottom.
Paper towel pat the meat to remove any blood. Then rub all over with olive oil, salt and pepper. Place in the dish and put in the oven. No oil or fat is required in the pan, rather you just pour in about a half a centimetre of water to keep the meat moist, adding more as it evaporates. Yes, that's it folks, about as easy as falling off a log.
You now need to be vigilant in checking that the temperature does not rise too far past 80 degrees Celsius. Also make sure there is water in the bottom of the pan. Bearing in mind it will take about 1 hour per kilo, make sure you plan your timing for the meat to come out an hour before it is going to be served – it is absolutely strategic that you give the meat a minimum one hour resting to achieve the optimum tenderness.
Invariably this is where people go wrong, serving meat or poultry for that matter, straight from the oven without resting it sufficiently. This hour will also give you the time and space in the oven to roast the vegetables, equally strategic.
You can turn the meat over about one hour in to the cooking time, and then around two hours begin inserting the meat thermometer to check on the progress. Rare roast beef is around 60 degrees Celsius in the middle, but be mindful that this cut will be thicker towards the middle and subsequently the meat will be more cooked at each end. This does in fact make it easier to cater for different tastes or degrees of rareness. Medium rare is closer to 70 degrees Celsius and I would be reluctant to cook it any further.
As the meat gets close to being cooked, turn the oven up to 200 degrees to sufficiently brown the outside (this will only take 10 minutes or so). Be sure to keep the water in the bottom of the pan topped up, as the juices will have seeped down and will make excellent gravy, although you do need skim off the fat.
Transfer the roast once cooked to a porcelain dish to rest, pouring all the resulting juices in to your roasting pan to add to the gravy. Thickening the gravy can be as simple as adding a little roux or just a few knobs of butter as you reduce the sauce over a top element.