Scrub the pork tongue well in clean water, then allow to soak in fresh water for 3 hours.
Meanwhile, combine white miso paste, brown sugar, saltpetre, juniper berries, cloves, 6 peppercorns, 2 bay leaves and water in a heavy pot. Bring pot to the boil, stirring constantly. When the sugar and salt have dissolved, remove pot from heat and allow the brine to cool. Transfer the cleaned tongue to a nonreactive (plastic or ceramic) container, and pour in the brine. Weigh down the tongue with a ceramic plate so it is completely submerged, then cover the bowl with cling film and refrigerate for 7 days.
Rinse tongue and pat dry, then place into a vacuum pouch and surround with the vegetables. Pour in as much stock as possible, then add the ½ teaspoon of peppercorns and 1 bay leaf, and seal the pouch on low.
Remove tongue from the pouch and gently remove the skin. Place in small container and cover with the broth from the pouch, then allow to cool. (If you don’t have enough broth to cover the pork, wrap it in some muslin and turn it over in the broth to soak it, then allow to cool in the liquid, turning occasionally to keep the cloth wet.)
In a pot, combine the water and isomalt over low-medium heat. When the mixture becomes a syrup, add the yoghurt and pork fat. Transfer mixture to a blender, and blend for 8 minutes to obtain a homogeneous curd. Refrigerate until required.