Crayfish Pies

Pastry

• 175 g plain flour plus extra for dusting
• 90 g unsalted butter cold, diced
• 1 pinch fine sea salt
• 1 egg yolk from medium egg
• 1 - 2 Tbsp water

Filling

• 40 g unsalted butter diced
• 1 garlic clove
• 6 spring onions cut in pieces (3 cm)
• ½ green pepper quartered
• 1 celery stalk quartered
• 200 g crayfish tails, cooked
  or 200 g prawns, cooked, peeled
• 20 g plain flour
• 220 g whole milk
• ¼ tsp Cajun spice mix
• ¼ tsp fine sea salt
• 1 pinch ground black pepper
• fresh parsley leaves roughly chopped, for garnishing (optional)