Heat a frying pan until hot.
Add the oil then sear the lamb briefly on each side.
Meanwhile, place the lamb stock, carrot, celery, onion and garlic in a pan and bring to the boil.
Add the lamb and poach for two minutes.
Remove and allow to stand.
For the fricassée, heat the frying pan until hot, add the olive oil, garlic, onion and thyme.
Cook for 2-3 minutes until just softened.
Add the savoy cabbage and stir-fry for five minutes.
Add the mushrooms and cook for a further 2-3 minutes.
Add 50ml/1¾fl oz of the poaching liquid.
Serve.