1 garlic clove, finely chopped
150g/5陆oz button mushrooms, quartered
1 small onion, chopped
small handful fresh parsley, chopped
200ml/7fl oz chicken stock
2 tbsp plain flour, plus extra for dusting
freshly grated nutmeg, to taste
2 tbsp olive oil
pinch salt
freshly ground white pepper
50g/2oz butter
1 free-range egg, beaten
300ml/陆 pint milk
500g/1lb 2oz ready-made shortcrust pastry
3 chicken breasts, skin and bone removed, cut into pieces