Crispy Lighter Bacon & Cheese Turnovers

Ingredients

• 6 sheets filo pastry (approx. $25\times 30\text{ cm}$ each)
• 4 lean bacon medallions, fat trimmed and chopped
• $60\text{ g}$ reduced-fat cheddar or mozzarella (or similar cheese)
• Low-calorie cooking spray or $1\text{ tsp}$ oil (for brushing)
• $1$ egg white, beaten (for brushing)
• Salt and pepper, to taste