Ham, leek & potato pie - Good Food Middle East

Ingredients

• 2 tbsp butter
• 1 large onion, finely chopped
• 3 leeks, finely sliced
• 2 large potatoes, cut into small cubes
• 2 tbsp plain flour, plus extra for dusting
• 300ml chicken or ham stock
• 100ml pot crème fraîche (or use leftover double cream)
• 2 tsp wholegrain mustard
• 200g cooked ham, shredded
• 4 bay leaves, optional
• 375g pack puff pastry
• 1 egg, beaten, to glaze (or use milk)