Preheat the oven to 200 degrees Celcius.
Cut parallel slits into each potato, stopping just before you cut through so that the slices stay connected at the bottom of the potato. I like to cut off the bottom part of the potato (1-2mm) so that it stands steady. I also usually use a spoon or put the potato in the handle of a plastic cutting board to make it easier not to cut all the way through the potato.
Place the potatoes on a baking sheet, brush with olive oil and sprinkle with sea salt. Bake in the oven for 45-60 minutes, depending on how large your potatoes are. If needed brush the potatoes once more after half the baking time. The potatoes are ready when they are soft all the way through and the edges are golden brown and crispy.
Meanwhile prepare the topping. Start by combining 2 tablespoons of creme Fraiche with grated horseradish or horseradish cream. Taste to check if more is needed. Set aside.
Next combine mayonnaise and ponzu.
Mash the avocado, combine with lemon juice, sea salt and black pepper.
When the potatoes are just about ready preheat a nonstick pan and fry the asparagus for 2-3 minutes. Just until warm and a bit softened, but still not soggy or soft all the way through. You can also use raw asparagus if preferred.
Peel the shrimps and rinse under water.
Slice the salmon sashimi into thin slices.
Divide the smoked salmon slice.
Take out the potatoes, place on a plate or cutting board.
Assembly by topping two potatoes with creme Fraiche, a piece of smoked salmon and seaweed salad. Followed by topping two potatoes with the horseradish cream, salmon sashimi slices and asparagus tops. Top the last two potatoes with avocado, shrimps, ponzu mayonnaise and furikake seasoning.