The idea for slow roasting a piece of beef came from a Mary Berry cookbook I'd been reading: Mary-Berrys-Family-Sunday-Lunches
The suggestion is that slow cooking is better for less tender cuts of beef. Now, I had a 2lb piece of topside which should have been pretty tender to start with. However, I fancied trying to cook the beef this way as it had the advantage that a precise cooking time wasn't quite so essential. So what if it spent an extra half hour in the oven whilst I faffed about getting the mash sorted...it shouldn't matter as it is at a lower temperature.
Suffice to say this was the most tender and flavoursome piece of beef I have ever tasted and it was very easy to do. If you've not tried it then do. Sorry there are no photos but I had been faffing (generally, not just the mash!) and was trying to get it served before Great British Menu started!
Start by sweating off chopped onion and garlic in a frying pan along with some mixed herbs and black pepper. Use this mix to cover the bottom of the roasting pan. Then quickly sear the beef in the frying pan before placing it in the roasting pan on top of the onion mix.
Next add some liquid to the roasting pan. About 400mls of beef and vegetable stock along with a generous slug of port. Cover with a well fitting lid and put in the oven. My piece of beef staying in for ~3½ hours at 160C.
While the beef rests on a plate pour the roasting liquid through a sieve and slowly add to a roux to make the gravy.