Fry the onion, carrots and celery in the
oil in a large frying pan until softened. Add
the mince, increase heat and cook for
5 mins or until well browned. Stir in the
tomato purée, Worcestershire sauce and
stock. Simmer for 5 mins until the sauce
has thickened slightly. Cool for 10 mins.
Heat oven to 200C/180C fan/gas 6.
Spoon the mixture into 4 individual pie
dishes or one large dish. Brush the dish
rims with egg, then lay the pastry on top
and trim. Seal edges with a fork and brush
the pastry with more egg. Poke a little hole
in the top and cook for 25-30 mins or until
the pastry is golden and risen.
Meanwhile, cook the peas in boiling
water, then drain and mash with the
mint sauce. Serve the pies with the hot
peas on the side.