Melt the butter along with the olive oil in a frying pan medium to high heat.
Crush the peppercorns and press the fillet steaks down on one side.
Place the steaks into the frying pan peppered side down for 2 – 3 minutes then turn and cook the other side for a further 2 – 3 minutes.
Remove the steaks from the pan and keep in the oven at 100 deg c.
Pour in the brandy into the pan along with the residue and flame off the alcohol.
Add the demi glace and stir in any left over peppercorns. Gradually add the beef stock.
Remove the fillet steaks form the oven.(the steaks should be pink and ready after about 10 mins). Add any juices to the sauce. Pour the sauce onto the serving plates
Place the fillet steaks on top of the sauce and serve along with chips and vegetables.