Creamy chicken, mushroom & fennel pie

Ingredients

• 1 tablespoon olive oil
• 2 cloves garlic, crushed
• 1 leek, sliced thinly
• 1 fennel bulb, sliced thinly
• 200 grams swiss brown mushrooms, quartered
• 1/2 cup (125ml) dry white wine
• 4 chicken breast fillets, chopped coarsely
• 300 millilitres pouring cream
• 1 tablespoon dijon mustard
• 1/4 cup fresh flat-leaf parsley, coarsely chopped
• 2 sheets puff pastry
• 1 egg, beaten lightly
• 1 tablespoon fennel seeds
• 1/2 teaspoon sea salt flakes