Preheat the oven to 220°C (200°C fan-forced)

Line a large oven tray with baking paper

Heat the oil in a small frying pan; cook the onion, garlic, celery and fennel seeds until soft but not brown

In a large bowl, combine mince, onion mixture, tomato paste, bread crumbs and parsley

Season with salt and pepper

Mix well until combined

Cut pastry sheets into 3 pieces

Spoon one-sixth of the mince mixture lengthways along centre of each pastry piece; roll pastry over to enclose filling

Cut each roll into 6 pieces; place rolls seam side down onto baking tray

Divide mince mixture into quarters

Spoon each quarter of mixture along centre of each pastry piece

Turn one long side of pastry over mince mixture; brush pastry flap with a little of the egg

Turn over other long side of pastry to enclose mince mixture

Brush rolls with egg and bake for about 25 minutes or until browned and cooked through

Stand sausage rolls 5 minutes before serving