Cut the foie gras into 6 slices each weighing 50g. Score one of the cut surfaces very gently with the tip of a knife in a criss cross pattern. Keep refrigerated.
For the compote: zest the orange with a knife or peeler.
Bring the water, cognac and sugar to the boil. Remove from the heat, add the tea bag and allow to infuse for 5 minutes.
Wrap the cinnamon, star anise and the orange zest in a piece of muslin and tie with a piece of string. Add this to the liquid.
Chop the prunes into small pieces and add to the liquid. Gently simmer until the liquid is almost evaporated and you have a compote. Remove the muslin bag with the spices and allow to cool.
For the brioche: toast the brioche under a hot grill or in a toaster until golden brown. Using a small circular pastry cutter, cut the brioche into 6 pieces.
Heat a frying pan until very hot.
Season the foie gras slices generously with Maldon sea salt.
Add the foie gras to the pan with the criss cross side down. Cook for 30 seconds, remove from the heat and quickly flip the pieces of foie gras over. Allow to finish cooking in the pan for 30 seconds more and then serve immediately on top of a piece of toasted brioche with a small quenelle of the prune compote.
«Be careful not to overcook the foie gras. The pan must be very hot to colour the foie gras but make sure to remove the foie gras from the pan as soon as it is cooked. »