Method:
1 Preheat oven 200°C fan-forced. In a mortar, pestle crush the peppercorns with a pestle.  Transfer to a plate and coat both sides of the rump. 
2 Heat oil in a frying pan over medium-high heat, add rump and cook for 4-5 minutes on each side for medium, or until cooked to your liking.  Remove to a plate, cover and stand for 5 minutes.  In the same pan add onion and cook for 1-2 minutes until softened, add red wine and reduce by half.  Add beef stock and cook for 2-3 minutes or until sauce thickens a little.  Add cream and simmer for a further 2 minutes without boiling.  
3 For potato rosti, grate the potatoes into a bowl and squeeze out as much moisture as possible, season with salt and pepper. Heat butter and oil in a medium frying pan over medium heat. Place greased egg rings into the pan and spoon in the potato.  Cook for 3-4 minutes until golden underneath then transfer to oven and roast for 10 minutes or until potato is cooked through.  Remove the egg ring.
4 Place rosti on a plate, top with peppered steak and pour over the sauce.  Serve.