Glamorgan cheese sausage rolls - Good Food Middle East

Ingredients

• 175g gluten-free flour (we used Doves Farm, widely available)
• 85g butter
• pinch cayenne pepper
• 1 egg yolk mixed with 3 tbsp cold water
• 100g gluten-free breadcrumbs (we used Dietary Specials Gluten-Free bread)
• 100g Caerphilly cheese, grated
• 1 small leek, finely chopped
• 1 tsp mustard seeds, crushed
• 3 egg yolks
• handful tarragon or thyme leaves (optional)