What is the best way to do a roast at home? Even using the same type of meat and similar weight of the meat, there are so many cookbooks with so many varying oven degrees and varying times in the oven. Please advise.

Florian Trento says: I use a convection oven at home. Pre heat the oven to 160 Degrees Centigrade, season the joint with salt and pepper and whatever else you like; place the joint onto a wire rack over a tray in the oven. This will allow the hot air to circulate freely around the meat. The tray will also catch the drippings. You can also roast vegetables in the tray at the same time, the dripping fat of the meat will add flavour! With a regular oven, sear the meat beforehand, use a tray only, increase to 170/180 Degrees Centigrade, turn the meat over every 20 minutes and baste frequently! 

Roast beef will need about 45 to 50 minutes per kilo. Once you feel that its done, stick a thin metal needle in the core, leave it for 10 seconds, remove and press the needle to your lower lip, if it's just lightly warm, it's done! Alternatively, and more reliable, use a thermometer, again stick it in the core of the roast, at 48 Degrees Centigrade it's rare; at 55 Degrees Centigrade, medium rare. Be careful, the internal temperature will continue to raise a few degrees after removing the roast from the oven. If in doubt, take it out! It can always be roasted some more, but if it's overcooked, it can't be fixed. For poultry, stick a metal needle in the leg join at the thickest part, when the juices run clear, it's done!

One of the most important factors for any roast - leave it to rest in a warm place for at least 15 minutes before carving. This is a must to avoid juices running out. Resting can be done on the opened door of the turned off oven, for example.

Many Middle Eastern recipes call for the spice sumac, but I haven't seen it for sale in Hong Kong. Can I substitute something else for the sumac?

Eric Hendry says:  A close substitute is lemon juice. Sumac is often used to substitute lemons when not in season. You may also try to find za'atar a popular spice mix, which also contains sumac. One supplier in Hong Kong for sumac is Red Mill Limited (94079494), they also carry an extensive list of arabic food products, wine and beer.

I like to buy meats in large batches because it is cheaper that way and I usually just store it in the freezer. For cuts such as sirloin and rib-eye, how long do they keep in the freezer and is there anything I should do when the meat arrives at my home?

David Goodridge says: I never recommend freezing meat. Ice crystals form when meat is frozen, it draws out the excess blood and so when the meat is being cooked, the appearance will look grey and dry. In Hong Kong, there is no need to buy in bulk when we have the convenience of supermarkets at our door step and individual cuts can be found at ease. Buy fresh and cook fresh is my advice.