1. Heat the oil in a large non-stick frying pan over high heat. Cook beef, in batchers, for 3 minutes until browned. Transfer to a bowl, cover to keep warm. 2. Add mushrooms to pan. Cook over medium heat, stirring occasionally, for 5 minutes until softened. Return beef to pan. Add Recipe Base and water, bring to the boil, stirring. Cover, reduce heat and simmer for 5 minutes until sauce has thickened slightly. 3. Stir in sour cream and cook until heated through. Serve with pasta and steamed green beans. Preparation time: 10 minutes. Cooking time: 20 minutes.