Dissolve sugar in vinegar with aromatics, boil, simmer, and cool before straining.
Soak cubed vegetables in 2 litres of salted water overnight, then rinse and drain.
Mix cornflour, turmeric, mustard, and chilli with 150ml vinegar to form a paste.
Thicken the paste with boiling vinegar, pour over vegetables, and seal in sterilized jars.
Boil ham hocks and trotters for ten minutes, then discard water and clean the pan.
Simmer hocks and trotters with wine, vinegar, shallots, and spices until the meat is tender.
Cool hocks in liquid for one hour, then remove meat and discard trotters.
Strain cooking liquid and boil rapidly until reduced to 650ml.
Line a 1.5-litre terrine mould with a double layer of cling film.
Mix shredded meat with capers, gherkins, and parsley, then press into the mould and add liquid.
Chill the terrine overnight in the fridge.
Combine bread ingredients and knead for 8 minutes until a soft dough forms.
Let the dough rise in a warm place for 90 minutes until doubled.
Shape the dough into a rectangle and prove for another 45 minutes.
Bake the bread at 220°C for 25 minutes until golden and hollow-sounding.
Beat soft butter with mustard powder and season to create the mustard butter.
Serve the sliced terrine with piccalilli, toasted bread, and the mustard butter.