Beef pie with crisp potato crust - Good Food Middle East

Ingredients

• 1 tbsp olive oil
• 500g beef braising steak, cut into chunks
• 1 onion, roughly chopped
• 250g pack oyster mushrooms, sliced if large
• 1 tbsp tomato paste
• 1 tbsp flour
• 100ml red wine
• 200ml hot beef stock, from a cube
• 350g potatoes, peeled
• 25g butter, chopped into small pieces