Ganache

1. Heat cream in a large, heavy-bottomed pot on low heat, until small bubbles appear around the edge and it starts to steam. You want to catch it right before it’s about to start to boil. Alternatively, you can heat in the microwave.
2. Remove from the heat and add black food colouring and petal dust. Mix with a whisk until combined. If it’s not black enough you can add more food colouring. I ended up adding about 30ml (maybe a little over kill) but you can start with 15ml and see how you go. It doesn’t effect the flavour of the ganache. 
3. Add chocolate, making sure it is covered by the cream. Cover and let sit for 5 minutes.
4. Stir vigorously using a whisk, until smooth.
5. If there are any lumps, put the pot back onto the stove over very low heat. Stir until the lumps have melted and the ganache is shiny. Alternatively, heat in the microwave in short intervals whilst stirring in between.
6. Add butter and stir through until smooth and creamy. Cover with plastic wrap and push it down into the ganache so it covers everything. Allow to sit until it comes to a runny mayonnaise consistency.