1.5kg(3.3lb) roasting jointtopside is a good choice
Instructions
Preheat oven to highest setting.
Combine all the ingredients from paprika to oil and mix into a paste
Add beef to a roasting tray, and rub chocolate spiced paste all over
Add beef to preheated oven.
Reduce oven to fan assisted 210C / 230C / 450 F / gas 8 and roast for 20 mins.
Then turn down to fan assisted 160C / 180C / 350F / gas 4 (if you open the oven door for a few seconds it cools faster).
Cook for about 10 minutes per 500g/1.1lb if you want it rare.
Check with your thermometer when it should be done. It will be about 50C / 122F in the middle (rare), 60C / 140F (medium) and 70C /158F (well done). A few degrees each side doesn’t matter.
Take out of oven and leave in a warm place to rest.
Notes
Use a quality meat thermometer to test the temperature.