Preheat the oven to 350˚F.
Place the potatoes in a saucepan and cover with cold water. Add a generous pinch of salt. Bring to a boil. Cook at a gentle boil until the potatoes are tender, about 15 minutes. Drain well. Pass the potatoes through a food mill or potato ricer into a large bowl (alternatively, mash the potatoes with a potato masher or fork until smooth).
Meanwhile, put the salmon on a parchment-lined baking sheet and season with salt and pepper. Bake until medium rare, about 15 minutes. Gently flake the salmon, discarding the skin. Add the flaked salmon to the potatoes, along with the scallions, garlic, ginger, tamari or soy sauce and toasted sesame oil. Season with salt and pepper. Form the mixture into ½-cup patties (makes about 9 patties). Do Ahead: The patties can be covered tightly and refrigerated overnight.
In a large nonstick skillet, heat ¼ inch of sunflower or safflower oil until shimmering. Working in batches, fry the patties over high heat, until browned and crisp, about 2-3 minutes per side. Transfer to a baking sheet and sprinkle with salt. Repeat with the remaining patties, adding more oil and adjusting the heat as necessary. Bake for 15 minutes, or until heated through. Serve with Yogurt Dill Sauce.