Place the pork onto a board and using a very sharp knife, score the skin into strips. You could ask your butcher to do this for you.
Rub the surface of the skin liberally with sea salt.
Place onto a baking tray and bake in preheated oven for 30 minutes.
Check the pork every 10-12 minutes.
Remove from the oven and allow to cool. Slice and set aside ready to assemble the Banh Mi.
To make pickled carrot, place vinegar and sugar in a saucepan over medium heat. Stir to dissolve sugar and remove from heat. Place carrot in a bowl, pour over vinegar mixture, add 1 tsp salt and stir to combine. Stand for 1 hour or until cool. Drain carrots, discarding liquid, and refrigerate until needed.
To assemble the Banh Mi, cut the rolls lengthwise and spread with butter, then some pate, top with slices of the pork.
Top with some carrot and daikon pickle, coriander leaves, spring onion, cucumber and then chilli to your taste and fried shallots for a little crunch.