The following ’shock freezing’ technique, which creates thin, flexible sheets of chocolate, is perfect for decorating Christmas logs. But be warned, this only works with real chocolate, not with baker’s coating.To master the technique it will be necessary to have a basic knowledge of chocolate tempering, which is also known as pre-crystallising.You can find everything you need to know chocolate tempering on the Barry Callebaut website: [http://www.callebaut.com]. Flexible chocolate sheets for finishing Christmas logs:When tempered chocolate is poured onto an ice-cold surface it gets a shock effect, which hardens the chocolate, but leaves it flexible enough to mould by hand.The technique may sound a bit complicated but give it a go and you will be amazed by the effects you can achieve.Try to get a piece of marble or granite from your local stone merchant (search on [http://www.yell.com] to find one in your local area). The stone does not need to be in perfect condition and the colour doesn’t matter. Try to get a long shaped piece measuring 60cm x 30cm.Put the stone in your freezer for at least two hours and take it out 10 minutes before you are ready to use it. Dry off any water that has condensed on the surface.Temper some dark chocolate couverture to 32-33?C and pour a small amount on to the marble. Spread it out as fast as possible with a pallet knife to a thickness of 2-3 mm. Immediately cut the chocolate to the desired length with your knife, then pass the knife underneath the chocolate to release it from the stone.Pick it up in your hands and fold it around your Christmas log or cakes. Repeat the process until the cake is covered with chocolate shards, then dust with cocoa powder followed by icing sugar. The effect is stunning.