For the sauce
- STEP 1
Score the fat on the beef in a criss-cross pattern. Mix together the five-spice and sugar, then season really well with salt and pepper. Rub all over the beef, then leave to marinate, preferably overnight.
- STEP 2
Heat oven to 200C/fan 180C/gas 6. When ready to cook, rub the oil all over the meat. Heat a griddle pan or, if the weather is good, a barbecue. You’ll need to leave the griddle pan for 10-15 mins to make sure it gets really hot. Place the meat, fat-side down, on the griddle and leave to cook for 5-10 mins until the fat starts to melt (the kitchen will probably get quite smoky so make sure you have an extractor fan turned on). Turn the meat over and cook for 5 mins more until it is well browned all over.
- STEP 3
Place in a roasting tin, then cook in the oven for 30 mins for rare (15-20 mins more for medium, or 30-40 mins more for well done). Cover and leave to rest for 15 mins.
- STEP 4
To make the sauce, trim the stalks from the coriander and place them in a pan along with the stock, garlic, ginger, oyster sauce and the white part of the spring onion. Bring to the boil, then leave to simmer and infuse for 10 mins. Strain, then chop the coriander leaves and place in the sauce along with the green spring onion slices to serve.