For the mousse:

1. Carefully cut the top off 6 oranges and scoop out them out, scraping the sides. Save the juice.
2. Place the chocolate in a large bowl and heat over a pan of simmering water (taking care that the bowl doesn’t touch the water beneath) until nearly melted or pop in the microwave for 30 second bursts until nearly melted. Stir well each time you remove from the microwave after a 30 second burst.
3. Add the cream to a saucepan and place over gentle medium heat. Heat the cream to just a gentle simmer with small bubbles foaming at the edge but not boiling.
4. Add the warm cream to the semi-melted chocolate and stir until it’s smooth and glossy.
5. Allow to cool a little, then stir in the egg yolk, orange zest and orange juice.
6. Beat the whites with an electric whisk until they form stiff peaks. Add the sugar and beat again until glossy.
7. Using a metal spoon, carefully fold a large spoon of egg whites in to the chocolate mix, and beat together. This will loosen it. Then pour this chocolate mixture into the rest of the egg whites and fold together gently, avoiding knocking any air out of the whites.
8. Nestle the oranges into a baking dish so that they stay upright. Pour the mousse into the oranges. Or pour mousse into a large bowl and leave to set in the fridge. The oranges will need less time to set, around 4 hours to overnight whereas the large bowl will need at least 8 hours to overnight.

For the meringue:

1. This is totally optional but I thought it looked gorgeous and added an extra element to the mousse and made it a little more original.
2. Add the egg whites to a large, clean bowl and whisk until foamy and bubbly. Then add the soft light brown sugar, one tablespoon at a time, whisking well in between. Keep going until all the sugar is added and the meringue is smooth and glossy. If you pinch a little meringue mixture between your fingers, you shouldn’t feel any grains of sugar. You want it totally dissolved.
3. Pipe on top of the chocolate mousse or spoon and smooth. Then use a blowtorch to brown the top and set it slightly. Enjoy immediately.