Prepare the day before:
Trim all the skin and fat from the meat. Cover with the salt and leave for 6 hours, turning regularly.
Rinse the meat, put in a large bowl, together with the vegetables and garlic, and pour in the wine, Madeira and port. Cover the bowl with cling-film and leave to marinate in the fridge for 24 hours.
On the day:
Remove the meat and vegetables, reserving the marinade. Pat the meat dry and dust it in a little seasoned flour.
Heat some oil in a large heavy-based ovenproof pan and brown the meat all over. Add the vegetables and sauté for a little longer, until light coloured.
In a separate pan, boil up the marinade and skim. Add the marinade to the pan with the meat and vegetables, together with the belly pork, orange rind and herbs. Cook very slowly on top of the stove for 1 hour.
Meanwhile, preheat the oven to 160C / 325F / gas mark 3.
Add the stock to the pan, cover and transfer to the oven for 4 hours. The pork is ready when it falls apart readily when a fork is inserted into it. Remove the meat from its cooking liquor and keep warm.
Strain the liquor through a fine sieve into a clean pan and bubble up until reduced to a sauce-like consistency. To finish the sauce, wave in the butter and liquorice.
Slice the meat and serve with the sauce and celeriac and asparagus mousseline. Garnish with cooked white and green asparagus. Top with asparagus crisps.
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