Preheat the oven to 200°C (390°F). Line a baking tray with parchment paper.
In a large mixing bowl, combine the chicken or pork mince, grated onion, green apple, carrot, crushed garlic, grated ginger, coriander powder, cumin powder, cardamom powder, turmeric, Keens curry powder, smoky paprika, tomato paste, celery leaves, parsley leaves, breadcrumbs, and egg. Mix until thoroughly combined.
Roll out the homemade puff pastry into a rectangle, about ½ cm thick. Cut the pastry into smaller rectangles, approximately 10cm x 15cm.
Place a portion of the prepared sausage mixture onto one side of each pastry rectangle, leaving space around the edges. Roll the pastry over the filling, sealing the edges by pressing firmly. Repeat with the remaining pastry and filling.
Place the assembled sausage rolls on the prepared baking tray. Brush the tops with egg yolk and sprinkle sesame seeds over each roll.
Refrigerate the assembled sausage rolls for 20-30 minutes to allow the pastry to rest and firm up.
Bake in the preheated oven for 25-30 minutes or until the pastry turns golden brown and crispy.
Once baked, remove the sausage rolls from the oven and allow them to cool slightly before serving.