about 240g/8戮oz leftover vegetables, such as carrots or Brussels sprouts, cut into chunks
1 tsp lemon juice
1 onion, chopped
300ml/10fl oz chicken stock (or 150ml/5fl oz leftover gravy mixed with 150ml/5fl oz chicken stock), plus extra if needed
3 tbsp plain flour, plus extra for dusting
1 heaped tsp wholegrain mustard
salt and freshly ground black pepper
300g/10陆oz plain flour, plus extra for dusting
225g/8oz butter, cold and cut into small cubes
40驳/1陆辞锄 butter
150ml/5fl oz double cream
1 free-range egg, beaten, for glazing
about 360g/12陆oz leftover meat, such as turkey, chicken or ham, sliced