Tarragon Crusted Chicken, Leek & Mushroom Pie - Ainsley Harriott

Ingredients

• 200g plain flour
• ¼ teaspoon salt
• 100g butter, chilled, cubed
• 2-3 tbsp cold water (with a squeeze of lemon)
• 1 tbsp finely chopped fresh tarragon
• egg, beaten with a dash of milk, to glaze
• 4 tbsp plain flour, seasoned with salt and pepper
• 500g chicken thighs, skinless and boneless, cut into bite-size pieces
• 2 chicken breasts, skinless, cut into bite size pieces
• 4 tbsp light olive oil
• 2 leeks, washed, sliced
• 1 clove of garlic, crushed
• 150g chestnut or button mushrooms
• 1 tsp chopped fresh tarragon
• 2 tbsp chopped fresh parsley
• zest of ½ lemon
• 120ml dry white wine
• 100ml chicken stock
• 120ml double cream
• salt & freshly ground black pepper