First, the honeycomb. Prepare a tin or heatproof dish by lining with lightly oiled baking parchment. Heat the sugar, syrup, 100ml water, and vinegar until it turns amber and reaches 150C ("the hard crack stage").

Add the bicarb, stir well, then pour into your lined tin. Leave to cool. If you want it to be cut into ordered shapes, cut with an oiled knife when it's nearly at room temperature. I like it to look a little rough and tumble, so cut it when it's cool.

For the mousse, break the chocolate into squares and melt gently. Meanwhile, whisk the egg whites until stiff.

Once the chocoalte is melted, remove from the heat and whisk in the egg yolks (they will cook if you keep them on the heat: you don't want scrambled egg in your mousse). When combined, gently add the egg whites, taking care not to knock out any of the air you have whisked in. Don't worry too much if it doesn't look very moussey yet, it will be lovely when it's set. Pour into serving glasses and leave in the fridge for two hours. Serve with honeycomb shards on top.