Finely chop onion and garlic and fry gently in a little oil until soft.
Add all pepper and fry for 30 seconds. Add red wine and brandy. The alcohol needs to be burnt off so be careful at this point. Once alcohol has reduced add beef stock and reduce by half. Once reduced add cream and reduce by half again.
The sauce is now ready to serve. Alternatively if the steak is being cooked in a pan, use the sauce to "de-glaze" the pan after the steak has rested in the pan.