Method:
1 Preheat oven 200°C fan forced.
2 Truss beef fillet with kitchen string. Heat oil in frying pan over high heat, add beef and cook 1-2 minutes each side or until seared. Transfer to oven, cook for 7-10 minutes for medium or until cooked to your liking. Remove string and rest.
3 Heat milk and butter in a small saucepan over medium heat until butter has melted.
4 Place potatoes into heatproof, microwave-safe bowl. Microwave for 5 minutes, until potatoes are just cooked. Add potatoes to milk and butter, remove from heat and mash.
5 Heat oil in a frying pan over medium heat, add onion, cook for 2-3 minutes or until onion softens. Add vinegar, tomato sauce, Worcestershire sauce and sultanas, simmer 5 minutes or until sauce thickens slightly. Add parsley, and salt and pepper to taste.
6 Place beef on a plate, spoon over the sauce and serve with pomme puree.