1 tbsp tarragon or marjoram, chopped
450g/1lb mushrooms, sliced
1 large onion, finely chopped
1.2办驳/2陆濒产 potatoes
100ml/3陆fl oz chicken or turkey stock
salt and freshly ground black pepper
30g/1oz butter
knob of butter
275ml/10fl oz double cream
1 free-range egg yolk
3 tbsp milk
675g/1lb 5oz leftover turkey and ham, cut into 2cm chunks