Mix the olive oil, lemon juice, worcestershire sauce and crushed garlic together and marinade the whole rump in this for 24 hours.
Pre-heat the oven to 180ºC.
Season the marinated rump with the mustard, salt, freshly ground pepper and fresh origanum.
Pour some boiling water into an oven roasting pan, place the pan rack on top and put the rump on the pan rack.
Roast in the oven for approximately 90 minutes for a medium done roast.
Let the roast rest for 20 minutes, whilst preparing the sauce.
Garnish with fresh origanum and serve with the sauce and a potato casserole.
For the sauce:
Heat the oil and butter in a pan and add the mushrooms.
Fry and when soft, reduce the heat and add the chopped spring onions and allow sweating for at least a minute.
Add the white wine and keep cooking until the volume has reduced by half.
Add the stock and the tomatoes and simmer slowly for ten minutes.
Add the thyme, salt, pepper and sour cream and heat through.
For more of PinkPolkaDots
recipes click here.