Preheat oven to 200°. Line a large, baking sheet with grease-proof paper.
In a large bowl, add beef, onion, breadcrumbs/panko, garlic, parsley, dried herbs, chilli flakes, egg and season generously.Mix ingredients together until well combined, then shape into 1” balls. Place onto baking sheet and set aside.
Roll your pyff pastry so it can be cut into long thin strips.Then, wrap around meatballs to look mummy-like and leaving a gap for the eyes (made from mustard).Now, wash the pastry with egg wash and bake until meatballs are cooked through and pastry is golden - approx 15 minutes. (*Cover with foil if the puff pastry starts to get too dark).Make two mustard dots for eyes on each mummy meatball and serve.