Scrub your potatoes well, and remove any dark spots. Cut them into chunks, roughly the same size. Set aside.
Bring a large pot of water to boil. Add the fine salt and potatoes, and cook until the potatoes are tender, about 12-15 minutes. Drain well, return them to the heat, and let any residual water evaporate off for 2-4 minutes or so. Remove from heat.
Use a ricer or potato masher to mash the potatoes to the consistency you like. Add butter, garlic and nutritional yeast, and mix well.
Fold in the sauerkraut, chives, pepper, and season with flaky salt, adding more to suit your taste. Say thank you and enjoy.