First make the ice cream by placing the cream and milk In a saucepan and bring to just under a boil. In a bowl whisk the sugar and egg yolks together until they are pale and thick. Pour the hot cream onto the sugar and egg mixture whisking all the time, then pour mixture back into a clean saucepan and cook over a low heat, stirring constantly with a wooden spoon until the mixture begins to thicken and coats the back of the spoon.
Strain the mixture into a bowl and set aside to cool completely. Stir in the orange curd and churn in an ice cream machine, keep frozen until ready to serve.
Preheat oven to 150°C / Gas 3.
Whisk the egg yolks and sugar together until they are pale and thick. Heat the cream in a saucepan and bring to just under a boil, then pour the hot cream onto the egg yolks, whisking constantly and leave to cool a little.
Dip some brioche slices into the cream mixture and make a layer in the bottom of an 8-inch square tin. Sprinkle chocolate pieces on top. Then place another layer of brioche on top and sprinkle with chocolate pieces again. Continue to do this until all the brioche is used and sprinkle the rest of the chocolate on top.
Pour any remaining cream and egg mixture over the bread and place the brioche tin in a deep tray and half fill with warm water, which goes half way up the sides of the tin.
Bake for at least one hour or until the top is crisp and all the liquid is set. Remove from the oven and water and set aside to cool. Remove the brioche from the tin and cut it into portions.
To serve, sprinkle the brioche with a dusting of sugar and flash under the grill to caramelise it, and serve with orange ice cream.