Roast fillet of beef with shallot & mushroom sauce - Good Food Middle East

Ingredients

• 1¼kg piece centre-cut beef fillets, trimmed
• 2 tbsp sunflower oil
• 1 tbsp olive oil
• 8 shallots, peeled and finely sliced
• 20 button mushrooms, finely sliced
• 75ml sherry vinegar
• 1 bottle fruity red wine, such as Rioja
• 1l good-quality beef stock
• 25g cold butter