Mary Berry Ham And Leek Pie Recipe

Ingredients

• 2 tbsp olive oil
• 2 large leeks, trimmed, sliced and rinsed
• 1 onion, chopped
• 2 garlic cloves, finely chopped
• 2 tbsp plain flour, plus extra for rolling
• 300ml chicken stock
• 400g cooked ham, diced (we used leftover meat from a cooked gammon joint)
• 100ml full-fat crème fraîche
• 1 tsp wholegrain mustard
• 375g puff pastry, thawed if frozen
• 1 large egg yolk, beaten