Blitz the sheet of nori in a blender or spice grinder until it is very finely chopped, almost powdered.
Peel and dice the potato. Place it in a saucepan and cover with cold water and a pinch of salt. Bring up to the boil and simmer it until it is tender. Drain very well and mash. Don't add any milk or butter when mashing it, you want it to be quite dry.
Squeeze the excess liquid out of the tofu (just with your hands is fine) then use your hands to crumble it into small pieces into a mixing bowl.
Drain the jackfruit or banana blossom then squeeze as much water as possible out of it over the sink. You want it as dry as possible. Use your hands to flake it into the bowl of tofu.
Heat the olive oil in a frying pan over a low heat. Add the Thai red curry paste, ginger, garlic and spring onions and cook for about 3 minutes until fragrant.
Add this mixture to the mixing bowl along with the mashed potato, nori, breadcrumbs, lime juice, soy sauce, coriander, salt and a good grinding of pepper.
Mix it all together really well until it is fully combined. It is easier to do this with your hands than with a spoon.
Divide the mixture into eight even pieces and shape each portion into a patty. (I use a scale for accuracy).
At this point you can simply fry the patties as they are, for about 5 minutes per side until browned and heated through.
If you want to add the breadcrumb coating, preheat the oven to 200°C/180°C fan/400°F/gas mark 6.
Place 50g (scant ½ cup) of the flour in a bowl with a pinch of salt. Gradually whisk in the milk to make a smooth batter.
Place the other 50g of flour in another bowl, and the breadcrumbs in a third.
Coat one of the fish cakes first in the flour, then in the batter and finally in the breadcrumbs. Repeat with the rest of the fish cakes, placing them on a baking sheet once they have been coated.
Heat a layer of oil in a frying pan. Fry the fish cakes for about 5 minutes per side until golden.
Drain them on kitchen paper then place them on a baking sheet and bake for 15 minutes until heated through.