Set the slow cooker to high setting or the oven to 140FanN/160C/310F/Gas4.

Chop the onion, carrots and celery stalk or herb.

Heat oil in a large frying pan over a medium heat and cook the onions and carrots for a few minutes then transfer to the slow cooker or a lidded casserole.

Brown the oxtail for a few minutes each side and transfer to the slow cooker or casserole.

Add a splash of wine to deglaze the pan and then stir in the flour for a minute. Pour in the rest of the wine and stock and bring to a boil.

Season with black pepper and add the bay leaf and fresh thyme leaves.

Cook in the slow cooker for about 8 hours or in the oven for about 3 ½, until the meat is tender.

Lift the oxtail from the pot and shred all the meat from the bones. When the meat is cool transfer to a covered container and refrigerate overnight.

Leave the stock to cool then cover and refrigerate overnight.

When you are ready to eat the soup use a spoon to gently scrape off any fat that has risen to the surface and discard.

Remove the bay leave and tip the stock into a liquidiser and process until smooth.

Tip in the reserved meat and heat through to a simmer.