Makes 6-8. I use a 120 ml ramekin. Oven set to 160 C/ 320 F. (1/2 US cup)
Put the eggs into a mixer with the sugar and beat till light and creamy. This is very important as it is the body of the mousse. They need to be pale and thick.
Meanwhile melt the chocolate with the cream over a double boiler ( or microwave) until just melted ( stand aside and keep warm). Fold the eggs through the chocolate mixture
Put 4 berries ( if using) onto the bottom of each ramekin and cover with mousse spread evenly between ramekins.
Boil the jug and pour some boiling water into a deep baking tray. Stand the ramekins in this making sure the water comes 1/2 way up the sides of the ramekins and no further. Put the tray into the oven. You can add the water while the tray is sitting in the oven. This may be safer
Set a kitchen timer for 13- 16 minutes. They may need 5 minutes more depending on the type of oven that you have- fan forced ( is hotter). They should be soft and just under cooked.
If you would like to prepare ahead make the mousses and refrigerate covered for up to a week. Take them out of the fridge and let them come to room temperature before baking. ( cold mousses will take a couple of minutes longer)