Preheat the oven to 180ºC and place a sheet of non-stick baking paper onto a large baking tray.
Put the minced beef in a large bowl.
Mince the garlic and onion together in the Wahl James Martin Grind and Chop using the chopper bowl, then add to the mince.
Next mince the carrot and celery in the same Grind and Chop bowl and add to the mince.
Place the torn bread into the Grind and Chop to make breadcrumbs, then add to the mince.
Put the cubes of Cheddar in the Grind and Chop and chop until like fine gravel, then add to the mince.
Beat the egg using the Grind and Chop and add to the mince.
Finally add the herbs, tomato puree, salt and pepper and mix thoroughly with your hand.
Unroll the pastry and transfer to the lined baking sheet.
Place the mince on top of the pastry and form into long brick shape leaving a 4 cm gap at each end.
Next take a knife and cut 1.5 cm strips down each side at a 45º angle.
Fold one end flap of the pastry over the end of the mince (trimming as necessary) and then draw up alternate strips of pastry to form a plait (wet the ends of the strips if necessary so they stick).
Once you get close to the end fold up the end flap of pastry (trimming as necessary) and then finish the plait with the end tucked in.
Finish off by beating an egg in the Grind & Chop and brush the egg wash over the plait.
Place on the middle shelf of oven and bake for 1 hour until pastry is golden and mince cooked.
Serve with vegetables or salad of your choice.