Heat a heavy bottomed pan and add the oil, carrots, celery and onion

Sweat for 4-5 minutes

Add the bouquet garni and all the alcohol and bring to the boil

Add the veal stock and then the trotters, cover with a lid and cook for 4-5 hours until soft

Remove carefully and cool

Meanwhile heat a non stick frying pan, add oil and the sweetbreads and sauté for   5-6 minutes until very crispy

Add the onions and mushrooms, season and set aside

Fold the sweetbreads into the chicken mousse and set aside

Place the trotters skin side down on tin foil  and place the chicken mouse filling into trotters and roll

Place the rolled up filling in a steamer and cook for 12-15 minutes