Prepare a baking pan or tray with grease-proof paper. You can use any size tin you like - mine is 24cm x 22cm (9½" x 8½") but make sure it is at least 5cm (2") deep, otherwise you could experience an overflow of molten sugar (see note 2).
In a heavy bottomed pan, add the sugar and syrup and heat on a medium temperature until the sugar starts to melt.
Stir often to make sure the mixture doesn't stick.
Continue until all the sugar has melted, is a runnier consistency and it is a nice golden caramel colour. DO NOT OVERCOOK! In a matter of seconds, it can burn.
Remove from the heat and then immediately add the baking soda, beating it in to the hot mixture, then pour into the prepared tin. Move fast because the sugar mixture starts to harden almost immediately.
Set to one side until it has hardened completely (about 30 minutes).
Melt the chocolate and then pour over the hardened honeycomb.
Allow the chocolate to set (it doesn't need to be in the fridge unless you are in a hurry).
When ready, break into shards (don't use a knife as it will just shatter). The pictures in this post show very large pieces for photographic purposes which were broken into smaller pieces before eating.