I am cooking rare roast beef, it weighs 0.71kg - how long do I cook it for and which is the best method - ie, do I seal it first? Whenever I cook beef it always ends up over cooked and dry - please help!!
It is very important to bring the meat up to room temperature before you cook it - don't cook it straight from the fridge.
Brown all over in a frying pan, then cook in a 180 degree oven for 35 - 40 minutes, at the most. Look at if after 30 minutes - it may be cooked enough.
Allow it to sit for at least 10 minutes before carving. You can put loose tin foil over it to keep the heat in.
I'm sure you'll probably receive some well intentioned advice.... but, the only way to assure to desired doneness is to use a meat thermometer. At 170 degrees F, the meat will be done to about a medium rare. However, take it out of the oven when reaching near 165 degrees F or so, since it will continue to cook after removing... The thermomemters are not expensive and be used for a number of other types of cooking... in my opinion... Best of luck!
I didn't have time to buy a thermometer, but did follow Ethel's advice - the beef was tender, pink & lovely and moist - thank you, it was thoroughly enjoyed!