cooking a beef joint

the groutch

is the generally advised 20 mins + 20mins per lb accurate?

am i bovvered

what cut of meat is it ?

the groutch

topside, 1.2kg, no fat

tSubh Dearg

I know it's probably a bit late now, but when I roast beef I generally use the timings of; 15 mins plus 15 mins per lb (stop now for rare) plus 15 mins (for medium rare) plus 15 mins (for well done).

So for example, if I had a piece of beef that weighed 2 lbs and I wanted it well done, I would cook it for 15 mins plus 30 mins plus 30 mins = 1 hr 15 mins.

Dizzyblonde

I don't think topside is one of the more tender cuts so you'd have to cook it for a lot longer than, say, fillet or sirloin. With this type of cut I usually bring it to the boil in a pot of water and simmer it for 20 minutes, then roast for around 2 hours (3 if it's a huge piece). it's the only way you can cook it until tender and still have it moist all the way through.
If you like your beef rare and cooked quickly you need to buy the very expensive cuts.