Puff Ham dan Keju

Bahan-bahan (18 porsi)

• 2 sheets puff pastry (, 25cm/10" square)
• 4 - 5 tbsp Dijon mustard
• 8 oz /250g shaved ham
• 2 cups shredded cheddar cheese ((or any other melting cheese) (Note 1))
• 2 egg yolks ((or 1 egg - Note 2))
• Oil spray