Properly employed, sugar helps balance the various flavours of sauces and other dishes. Chinese sugar comes in several forms: rock or yellow lump sugar, brown sugar slabs and as maltose or malt sugar. I particularly like to use rock sugar, which is rich and has a more subtle flavour than refined granulated sugar. It also gives a good lustre or glaze to braised dishes and sauces. You can buy this in Chinese grocers. You may need to break the lumps into smaller pieces with a wooden mallet or rolling pin. If you cannot find it, use white sugar or coffee sugar crystals (the amber chunky kind) instead.