3 carrots, roughly chopped
3 celery sticks, roughly chopped
3 white onions, roughly chopped
4 large parsnips, peeled
2 large potatoes
8 sprigs thyme
3 tbsp plain flour
about 500ml/18fl oz beef stock
salt and freshly ground black pepper
2 tbsp black mustard seeds
6 tbsp olive oil
125驳/4陆辞锄 butter
2kg/4lb 8oz cubed beef (mixture of chuck, skirt and shin)