Begin by melting the chocolate over a pan of just simmering water in a heat proof bowl - use more milk chocolate if you like - be reassured this is not a sickly sweet frosting at all!

Put the sugar with 100ml of water in a tall heavy bottomed saucepan with a sugar thermometer clipped in place.

Bring the sugar to a boil rapidly and as the sugar approaches 121˚C (which takes me upto 10 minutes of standing and watching - do NOT leave boiling sugar unattended!) start whisking your egg whites and salt on medium speed.

When the sugar has caramelised and the egg whites are frothy and tripled in volume, turn the stand mixer speed up to high and very very slowly but in a steady steam, pour the caramel between the side of the bowl and the revolving whisk.

It may sizzle and splash a tiny bit but don't be scared!

Once all the boiled sugar has been incorporated, continue whisking on high until the bowl feels room temp again (careful - a metal bowl will heat up on adding the sugar)

Turn down the speed to medium and spoon in the butter a teaspoon at a time slowly but surely

Add in the vanilla then pour in the cooled but melted chocolate.

Turn up the speed once more and whip until thick and creamy - it may only take another 20-30 seconds.

Keeps well for 3 days covered in the fridge or frozen for one month - bring to room temp before using & beat well to bring back to desired consistency.