Grown Up Ham and Cheese Finger Sandwiches Recipe | Food Network UK

Ingredients

• 120ml water
• 8 thin slices prosciutto
• 1/2 bunch watercress
• 1 tbsp Dijon or whole grain mustard, apple butter or chutney
• 115 to 170g aged Gouda
• 1 large or 2 small green apples
• Extra-virgin olive oil
• 8 slices thin white bread
• 1/2 small red onion, very thinly sliced
• 1 1/2 tbsp brown sugar
• 3 tbsp cider vinegar
• Freshly ground black pepper