- Place the fingerling potatoes in a medium pot and cover with water. Boil until tender, 7 to 8 minutes. Remove from the heat and drain.
- Transfer the potatoes to a blender along with the cashews, reserved soaking water, nutritional yeast, sauerkraut, coconut oil, onion powder, and garlic powder. Blend until smooth, then transfer to the medium pot.
- Cook over medium heat, stirring occasionally, until heated through, about 5 minutes. Reduce the heat to medium-low. Add the wine and cook for another 5 minutes.
- In a cup or small bowl, whisk together the water and tapioca powder. Add to the pot and cook, stirring constantly, until the fondue is thick and glossy.
- Add salt, if desired. Remove from the heat and transfer to a double boiler or a fondue pot over a tea light candle. Serve immediately with the dippers of your choice. Leftovers can be refrigerated in an airtight container for 1 to 2 days.