Wash the knuckles and heads thoroughly three times. Soak for thirty minutes then wash again.

Place these ingredients in a pan and cover with water. Chop the vegetables to a mirepoix and add to the pan along with the thyme and peppercorns.

Cook slowly simmering for 3-4 hours until tender. The small bone should be easily pulled out when the knuckles are cooked.

Take the meat out of stock and drain. Remove the skin and bone, flake down and place on a tray to cool.

Reduce the ham hock liquor until flavour comes out, then clarify with the egg whites.

Whilst the liquor is hot, add egg whites and ice whisked together and slowly bring the mixture to the boil.

When the egg has formed a thick skin, pass the liquor through muslin. The liquor should now be transparent.

Place all meat in a kilner jar and gently pour on cool stock. Leave to set in the fridge and eat within a week