Pre-heat the oven to 220 deg. c/ 425 deg.f/ gas mark 7.
Heat the butter and vegetable oil in a large pan and stir-fry the onion until soft. Stir in the plain flour and continue to stir fry for one minute. Add the white wine, vegetable stock and double cream and bring to the boil, stirring. Simmer until thickened. Stir in the Quorn pieces, the defrosted mixed veg, the button mushrooms and allspice. Season and simmer for 20 mins. Cook rectangles of the puff pastry in the oven for 20 mins and served with vegetables. For a substantial meal, serve with rice.