Grilled pork loin with sea spaghetti & seaweed butter potatoes

1 thick piece of pork loin (approx. 300-400g), preferably with a little fat
A handful of fresh Riementang (or dried, previously soaked)
4-6 small boiled potatoes (waxy)
2 tbsp butter
1-2 tsp dried seaweed powder (e.g. from nori, dulse or a seaweed mix)
salt & pepper

Place the fresh seaweed in a metal bowl or fireproof dish and pour hot water over it. Then place the bowl on the grill and let the seaweed steep slowly in the hot water with the lid closed until it is soft but still firm to the bite - this takes about 10-15 minutes. Do not cook!
Season the meat all over with salt and pepper and rub with a little oil. Grill on the barbecue over a direct heat, then finish cooking over an indirect heat for about 15-20 minutes, depending on the thickness. Leave to rest before slicing.
While the meat is resting, melt the butter in a small pan or metal bowl and mix with the seaweed powder. Roast the cooked potatoes on the grill and then toss them in the seaweed butter. This creates a wonderfully umami-salty flavor that goes perfectly with meat and the sea.
Cut the pork loin into thick slices and serve with the warm sea spaghetti and potatoes.