Cook the potatoes until they are done, let them cool down and peel them. Finely chop the onion. Slice the potatoes and mix with the chopped onion.
For the vegan mayo dressing, put the soy drink, mustard, paprika powder, salt and apple cider vinegar in a tall container and mix. Slowly pour in the vegetable oil while blending.
Add the mayo dressing to the potatoes and stir. Season to taste with parsley and finely chopped fresh chives. If possible, let the potato salad cool and steep for a few hours before serving.